ABSTRACT The objective was to assess the effect of changes in leisure time physical activity on high-density lipoprotein cholesterol (HDL-C) levels among community-based participants. Data from a randomly selected cohort were obtained in 1987, with follow-up measurements in 1991. Two medium-sized South Carolina communities were study sites. The study population included women participants of the 1987 survey and assessment who were available for follow-up measurements in 1991, including 1,003 white and 348 African American women aged 18–89 years. Changes in HDL-C levels in four leisure time physical activity groups, adjusting for age, education, body composition, baseline HDL-C levels, and cigarette smoking status, were measured. Overall, over the 4-year period, mean HDL-C levels increased among women in both age groups, but this change was significant only among women age 50 and older. However, HDL-C increases for inactive women who increased their reported physical activity level at the time of the follo...