OBJECTIVES: In 2001, persons throughout Brazil who were 40 years old or older were invited to participate in community screening for diabetes as part of the Brazilian Ministry of Health's Plan for the Reorganization of Care for Arterial Hypertension and Diabetes Mellitus. This report describes the overall participation rate and positivity rate of the screening campaign, as well as factors associated with the level of participation among the municipalities in Brazil. METHODS: Screening test positivity was defined as a fasting glucose of >100mg/dL or a casual glucose of > 140mg/dL. Screening data were obtained from the Ministry of Health and were analyzed for each municipality. RESULTS: Out of the 5 561 municipalities in Brazil, 5 301 of them (95.3%) participated and reported results. Of the 30.2 million persons in the target population, 22.1 million of them (73.0%) were tested, and 3.5 million of the persons tested (15.7%) were positive. Higher odds of a high population participation rate (> 80%) were seen in municipalities that were of small size (risk ratio (RR) = 5.0, comparing extremes), were located in the North region of the country (RR = 1.8), were located outside of a metropolitan region (RR = 1.4), and had a higher proportion of their population who had completed elementary school (RR = 1.2) (P <0.05). There was a parallel increase in glucose testing nationwide during and immediately after the campaign, presumably in part for diagnostic confirmation of cases identified during screening. CONCLUSIONS: The massive response to the campaign attests to the potential that this type of program has to raise diabetes awareness and to set the stage for capacity-building at the primary care level.