This review discusses the health effects of coarse airborne particles (PM10 > 2.5 µm) compared to fine particles (PM2.5 < 2.5 µm). Traditionally, studies have focused on PM10 or PM2.5, but recent research has examined the separate impacts of coarse particles. Time series studies show that coarse particles may have an independent effect on daily mortality, though evidence is stronger for fine particles in most urban areas. Long-term studies have not found a clear association between coarse particles and survival. In studies of chronic obstructive pulmonary disease (COPD), asthma, and respiratory admissions, coarse particles have a strong or similar short-term effect to fine particles, suggesting they can trigger adverse lung responses. There is also evidence of an association between coarse particles and cardiovascular admissions. The review concludes that coarse particles should be studied and regulated separately from fine particles. Coarse particles have different sources and compositions compared to fine particles. They are mainly generated by mechanical processes and can vary in size up to 100 µm. Coarse particles are often dominated by crustal material, such as silicates, but this depends on the specific sources. Recent studies have enabled the investigation of fine and coarse particles separately, allowing for a better understanding of their individual health effects. The correlation between fine and coarse particles is often low, making it easier to separate their effects in field studies. Toxicology studies have also shown that coarse and fine particles may have different toxicities. Studies on mortality show that coarse particles may have some effect on mortality, particularly in arid regions. However, few studies have analyzed fine and coarse particles together. Some studies found that the effects of coarse particles were reduced after adjusting for fine particles, while the effects of fine particles remained. In Santiago, coarse particles were more important than fine particles in summer. Studies on morbidity show that coarse particles have a strong or similar short-term effect on respiratory and cardiovascular admissions compared to fine particles. Coarse particles may contribute to respiratory and cardiovascular morbidity, leading to increased hospital admissions. However, long-term effects of coarse particles on morbidity are not well understood. Exposure assessment is challenging due to the spatial variability of coarse particles. Studies have shown that coarse particles can have higher spatial correlations than fine particles in some cases. However, further data is needed to fully understand the spatial correlation of coarse particles. Policy considerations highlight the importance of studying and regulating coarse particles separately from fine particles. The health effects of coarse particles have been largely overlooked, but they present an important challenge for further study using epidemiological, toxicological, and chemical approaches. Coarse particles are also important in regulatory processes and control measures.This review discusses the health effects of coarse airborne particles (PM10 > 2.5 µm) compared to fine particles (PM2.5 < 2.5 µm). Traditionally, studies have focused on PM10 or PM2.5, but recent research has examined the separate impacts of coarse particles. Time series studies show that coarse particles may have an independent effect on daily mortality, though evidence is stronger for fine particles in most urban areas. Long-term studies have not found a clear association between coarse particles and survival. In studies of chronic obstructive pulmonary disease (COPD), asthma, and respiratory admissions, coarse particles have a strong or similar short-term effect to fine particles, suggesting they can trigger adverse lung responses. There is also evidence of an association between coarse particles and cardiovascular admissions. The review concludes that coarse particles should be studied and regulated separately from fine particles. Coarse particles have different sources and compositions compared to fine particles. They are mainly generated by mechanical processes and can vary in size up to 100 µm. Coarse particles are often dominated by crustal material, such as silicates, but this depends on the specific sources. Recent studies have enabled the investigation of fine and coarse particles separately, allowing for a better understanding of their individual health effects. The correlation between fine and coarse particles is often low, making it easier to separate their effects in field studies. Toxicology studies have also shown that coarse and fine particles may have different toxicities. Studies on mortality show that coarse particles may have some effect on mortality, particularly in arid regions. However, few studies have analyzed fine and coarse particles together. Some studies found that the effects of coarse particles were reduced after adjusting for fine particles, while the effects of fine particles remained. In Santiago, coarse particles were more important than fine particles in summer. Studies on morbidity show that coarse particles have a strong or similar short-term effect on respiratory and cardiovascular admissions compared to fine particles. Coarse particles may contribute to respiratory and cardiovascular morbidity, leading to increased hospital admissions. However, long-term effects of coarse particles on morbidity are not well understood. Exposure assessment is challenging due to the spatial variability of coarse particles. Studies have shown that coarse particles can have higher spatial correlations than fine particles in some cases. However, further data is needed to fully understand the spatial correlation of coarse particles. Policy considerations highlight the importance of studying and regulating coarse particles separately from fine particles. The health effects of coarse particles have been largely overlooked, but they present an important challenge for further study using epidemiological, toxicological, and chemical approaches. Coarse particles are also important in regulatory processes and control measures.