The objective of the study reported here was to assess the association between air pollution and daily diabetes mortality in Shanghai. Death records were collected for all individuals who lived in the Zhabei district of Shanghai and died from diabetes from January 1, 2001, to December 31, 2002. The authors used a time-series approach to study the acute effects of air pollution on diabetes mortality after controlling for long-term trends, weather variables, and day of the week. Each increase of 10 microg/m3 in PM10, SO2, or NO2 was found to correspond, respectively, to a 1.006 (95 percent CI: 1.000-1.012), 1.011 (95 percent CI: 0.990-1.032), or 1.013 (95 percent CI: 1.000-1.026) relative risk of diabetes mortality in Shanghai. The air pollutants also were observed to have a greater effect on diabetics than on nondiabetics. These findings provide new evidence for the association between air pollution and diabetes mortality risk, and suggest that diabetics are more susceptible to air pollution than are nondiabetics.