Obesity has been recognised as a major public health concern due to lack of physical activity and a sedentary lifestyle. The aim of this study was to determine the status of physical activity level and body mass index (BMI) among youth living in low-cost housing in Kuala Lumpur. The respondents were youths aged between 15 and 25 (19.80, SD=3.17) years old and consisted of 214 males and 172 females. The BMI value was determined through the ratio of body weight and height, while the level of physical activity was measured using the International Physical Activity Questionnaire (IPAQ). The descriptive analysis showed that the mean BMI of male respondents was (22.65, SD=3.11) kg/m² and (23.73, SD=3.30) kg/m² for the females. A total of 227 (58.80%) of the respondents had low-level physical activity (441.57, SD=81.64) MET-min·w^k-1. Correlation analysis showed that there was positive correlation between age and BMI (r=0.18, p<0.001), meanwhile, there was negative correlation between physical activity and age (r=-0.27, p<0.001), and between physical activity and BMI (r=-0.24, p<0.001). The study also found the obese group (obese class I) had lower physical activity than other group at the significant level of p<0.05, F (4, 381)=10.483, p<0.001. The youth living in low-cost housing demonstrated poor physical activity level. Therefore, efforts should be made to promote the importance of a healthy lifestyle and being physically active in order to avoid obesity and other health problems.