The ability of young adults with mental retardation to successfully transition from high school to adulthood as integrated and independent members of the community is conditional upon their health status, which is directly linked to their physical activity level (Heath & Fentem, 1997). Career assistance transition programs are realistic settings where instruction about physical activity may occur and the engagement of physical activity may be facilitated. The purpose of this study was to measure the physical activity levels in a sample of young adults with mild mental retardation participating in a career transition assistance program. Fifteen young adults (6 males, 9 females; ages 18-24 yrs) volunteered to participate. Physical activity levels were measured using a uniaxial accelerometer (Actigraph LLC, GT1M Model). Participants wore the monitor during work hours at their job site for 7 weekdays. Participants were assigned to four different job sites or enclaves by their supervisors in the program. Accelerometer counts per minute were categorized according to light, moderate, vigorous, and very vigorous activity. Height and weight measures were taken to calculate body mass index. Means and standard deviations were calculated for descriptive purposes. Significance was set at p£.05. Kruskall-Wallis tests revealed no significant difference in physical activity levels according to enclave or gender. Participants spent a majority of percent time in light physical activity (97.6±1.2). Six participants (2 males, 4 females) and 7 participants (3 males, 4 females) were overweight and obese, respectively. The results of this study indicate that participants engaged in activities, job-related and other, that did not require sufficient moderate to vigorous physical activity levels that would benefit participant health. The data suggest that physical activity is not an integral component of the career transition assistance program within this study. For young adults to engage in healthy lifestyles throughout adulthood and perform in realistic job conditions, it is recommended that that physical activity instruction and engagement become an integral part of career transition assistance programs. Keyword(s): adapted physical activity, adult physical activity/fitness, worksite