The South Florida Program on Aging and Health was initiated in 1992 with the aim to assess physical and mental health of the elderly in Dade County and provide a basis for public health policy. This report describes the methodology applied in the study and preliminary screening results in a probability sample of 2,400 African American, Cuban American and white non-Hispanic American elderly men and women. Of 2,013 participants screened by May 1995, 11.5% had cognitive impairment. An increase in prevalence from 4-7% to 25-36% with advancing age was found among men and women of each group, from the youngest (65-74) to the oldest (85+ years). Male and female prevalences were similar but vary by ethnic group and age.