This article reviews the advancements in nanostructured metal oxide-based acetone gas sensors for breath analysis. Acetone, a volatile organic compound (VOC) often detected in exhaled breath, is a significant biomarker for various metabolic disorders, including diabetes. The detection of acetone in breath can aid in early diagnosis and intervention, reducing healthcare costs and mortality rates. Nanostructured metal oxides, particularly SnO₂, have emerged as promising materials for acetone sensing due to their high sensitivity, selectivity, and response times. The review discusses the critical factors affecting sensor performance, such as acetone concentration levels and operational temperature, and highlights the challenges of humidity and selectivity. Various nanostructures, including flower-like, hollow microspheres, nanobelts, and hierarchical mesoporous structures, have been explored to enhance acetone detection. These structures provide larger surface areas, improved gas diffusion, and enhanced electron transport, leading to better sensitivity and selectivity. The incorporation of noble metals, two-dimensional materials, and catalytic materials further improves sensor performance. The article also presents specific examples of SnO₂-based sensors, including Ag-decorated SnO₂ hollow nanofibers, Y-doped SnO₂ prismatic hollow nanofibers, and Eu-doped SnO₂ nanofibers, which demonstrate high sensitivity and selectivity towards acetone. Overall, the review underscores the potential of nanostructured SnO₂ sensors in advancing the field of breath analysis for metabolic disorder diagnosis and management.This article reviews the advancements in nanostructured metal oxide-based acetone gas sensors for breath analysis. Acetone, a volatile organic compound (VOC) often detected in exhaled breath, is a significant biomarker for various metabolic disorders, including diabetes. The detection of acetone in breath can aid in early diagnosis and intervention, reducing healthcare costs and mortality rates. Nanostructured metal oxides, particularly SnO₂, have emerged as promising materials for acetone sensing due to their high sensitivity, selectivity, and response times. The review discusses the critical factors affecting sensor performance, such as acetone concentration levels and operational temperature, and highlights the challenges of humidity and selectivity. Various nanostructures, including flower-like, hollow microspheres, nanobelts, and hierarchical mesoporous structures, have been explored to enhance acetone detection. These structures provide larger surface areas, improved gas diffusion, and enhanced electron transport, leading to better sensitivity and selectivity. The incorporation of noble metals, two-dimensional materials, and catalytic materials further improves sensor performance. The article also presents specific examples of SnO₂-based sensors, including Ag-decorated SnO₂ hollow nanofibers, Y-doped SnO₂ prismatic hollow nanofibers, and Eu-doped SnO₂ nanofibers, which demonstrate high sensitivity and selectivity towards acetone. Overall, the review underscores the potential of nanostructured SnO₂ sensors in advancing the field of breath analysis for metabolic disorder diagnosis and management.