The review examines the health effects of nitrate in drinking water, focusing on recent epidemiological studies published between 2005 and 2018. Nitrate levels in water resources have increased globally due to agricultural practices, leading to concerns about potential health risks. The regulatory limit for nitrate in public drinking water was set to prevent infant methemoglobinemia, but other health effects, such as cancer and birth defects, were not initially considered. Recent studies have evaluated the relationship between nitrate intake from drinking water and various health outcomes, including colorectal cancer, bladder cancer, breast cancer, thyroid disease, and neural tube defects. The strongest evidence for adverse health effects is for colorectal cancer, thyroid disease, and neural tube defects, with many studies observing increased risks at nitrate levels below regulatory limits. Future research should improve exposure assessment and consider individual factors affecting endogenous nitrosation. The review also discusses the impact of nitrate on methemoglobinemia, adverse pregnancy outcomes, cancer, thyroid disease, and other health effects.The review examines the health effects of nitrate in drinking water, focusing on recent epidemiological studies published between 2005 and 2018. Nitrate levels in water resources have increased globally due to agricultural practices, leading to concerns about potential health risks. The regulatory limit for nitrate in public drinking water was set to prevent infant methemoglobinemia, but other health effects, such as cancer and birth defects, were not initially considered. Recent studies have evaluated the relationship between nitrate intake from drinking water and various health outcomes, including colorectal cancer, bladder cancer, breast cancer, thyroid disease, and neural tube defects. The strongest evidence for adverse health effects is for colorectal cancer, thyroid disease, and neural tube defects, with many studies observing increased risks at nitrate levels below regulatory limits. Future research should improve exposure assessment and consider individual factors affecting endogenous nitrosation. The review also discusses the impact of nitrate on methemoglobinemia, adverse pregnancy outcomes, cancer, thyroid disease, and other health effects.