Background : The present study aimed to explore associations of physical activity (PA), waist circumference (WC) and body mass index (BMI) with subjective health in a nationally representative sample of Belgian adults. Methods : Data from the 2004 Belgian Food Consumption Survey were used. A face-to-face questionnaire about sociodemographic and socioeconomic characteristics, general health, subjective health, lifestyle and PA was completed. Weight and height were self-reported, and WC was measured in orthostatic position. PA was assessed by the short International PA Questionnaire. Results : In total, 3208 individuals (49.9% women) were included in the study. About 41.3% of the Belgian population did not meet the minimum recommendations for PA, whereas 24.8% of the population engaged in health-enhancing PA. In total, 29.5% of the population was overweight, 10.1% was obese and 33.2% of the population had an excessive WC. About 23.6% of the population rated their health as poor. Obese individuals were significantly less likely to report good subjective health than those with normal BMI [odds ratio (OR) = 0.538; 95% confidence interval (CI): 0.390–0.742]. This association was also identified for men and women separately. Further, both individuals who participated in health-enhancing PA and those who participated in recommended PA reported significantly better subjective health than insufficiently active individuals (OR = 2.533; 95% CI: 1.952–3.287 and OR = 1.543; 95% CI: 1.256–1.894, respectively). Conclusions : A strong association was found between PA and subjective health, and in addition, a significant negative association was found between BMI and subjective health. There was no relationship between WC and subjective health among Belgian adolescents and adults.