Background: Identification of reliable predictors of leisure time physical activity (LTPA) will enable healthcare providers to intervene and change the patterns of LTPA in the population to improve community health. Objectives: The objectives of this study were to determine prevalence and pattern of LTPA among adult Saudis aged 18-65 years, and to define the socio-demographic determinants that correlate with LTPA in Al-Hassa, Saudi Arabia. Subjects and Methods: A cross-sectional study of 2176 adult Saudis attending urban and rural primary health care centers were selected using a multistage proportionate sampling method. Participants were personally interviewed to gather information regarding socio-demographics, physical activity pattern using the Global Physical Activity Questionnaire (GPAQ). Physical activity (PA) in each domain was expressed in metabolic equivalents (METs). Results: The median total METs minutes/week for LTPA for both genders was 256, higher for men (636 METs minutes/week) compared to women (249METs minutes/week). Overall, only 19.8% of the total PA was derived from LTPA. Of the sampled population 50.0% reported doing no leisure activity. Using the cut off of 600 METs-minutes/day or 150 minutes of moderate intensity over 5 or more days/week, only 21.0% of the included sample were considered as being sufficiently active and 10.4% were in the high active category with beneficial health effects. Multivariate regression analysis showed that male, younger age (<35 years), absence of chronic disease conditions and moderate level of total PA were significant predictors for being active in the LTPA domain. Conclusion: The prevalence and intensity of LTPA among the included sample demonstrated low levels. Nearly 80% of the included sample population did not achieve the recommended LTPA level with beneficial health effects. Female gender, urban residence and associated chronic diseases correlated with a low LTPA.