A total of 1,011 clinically asymptomatic adults older than 20 years of age, with a minimal fasting of one hour, were screened for diabetes mellitus. This group was selected from a community medical service. The presence of diabetes in first degree relatives (parents, brothers/sisters and children) was investigated by interrogation of the subjects. Weight, height, and the waist and hip perimeters were measured, and the body mass index and the waist/hip ratio were calculated. Obesity was present in 26% of the population and 35.6% had a relative with diabetes mellitus, but 53.8% were younger than 40 years. A capillary blood sample was taken and glucose was measured by a reflectometer glucometer. Individuals with blood glucose levels of 160 mg/dL or higher were appointed for a fasting venous blood sample and glucose was analyzed using the glucose oxidase method. ii the glucose levels were >140 mg/dL, a second fasting venous blood sample was taken 1-2 weeks later, if both results were >140 mg/dL a diagnosis of diabetes mellitus was established; otherwise it was considered non diagnostic for diabetes mellitus. A total of 17 were detected with >160 mg/dL by the glucometer and 12/17 persons were diagnosed with diabetes mellitus (1.2%). No person younger than 30 years was detected (n = 307), but 3/237 were detected in the thirty years group (1.26% for this group) and 9 persons were older than 40 years, 1.2% of the total group. Capillary glucose measurements may be used for screening of populations selecting those who require to be submitted to diagnostic tests.