The burden of non-communicable diseases is increasing in Malaysia. Insufficient Physical Activity, which is an important risk factor for non-communicable diseases, is less researched in Malaysia. We aimed to assess the level of physical activity and identify its correlates. An online survey was carried out during October, 2011 in the University Tunku Abdul Rahman by the opinion poll research committee. Young adults answered the Short International Physical Activity Questionnaire and a questionnaire about factors according to a socio-ecological model which was adapted from published studies. Metabolic equivalent (MET)-hours and MET-minutes were calculated. Physical activity was classified as sufficient when MET-minutes were > 840. The mean age of the 474 participants was 22.4 years (S.D. = 4.7), and 253 (53.4%) were females. Their mean and median of MET-hours of PA done during the previous seven days were 31.36 (S.D., 52.19) and 14.7 (IQR, 5.77-32.07), respectively. Physical activity done was sufficient among 242 (51.1%) participants. Using univariate analysis, being male, good self-rated health, positive intention, self-efficacy, perceived benefits, social support, and availability of facilities were associated with sufficient physical activity. Using multivariate analysis sufficient physical activity was associated with participants' intention (OR 0.75, 95% CIs 0.64, 0.88), self-efficacy (OR 0.91, 95% CIs 0.85, 0.97) and facility availability (OR 0.81, 95% CIs 0.73, 0.91). The proportion of participants with sufficient physical activity was low. Positive intention and self-efficacy associated with sufficient physical activity should be supported by availability of facilities and a safely-built environment. A nationwide survey about physical and associated socialecological factors is needed to design rational health promotion strategies.