Aim: The objective of this study was to determine associations between physical activity, dietary fiber intake, water and fluid intake, and constipation as well as other possible risk factors for constipation in adults. Method: A cross-sectional study was conducted in 4561 (1812 male and 2749 female) adults, aged between 18-65 years, living in Ankara, Turkey. Participants having three or fewer bowel movements per week were considered constipated. Dietary fiber and fluid intake data were ascertained from a 62-item food frequency questionnaire (FFQ). The International Physical Activity Questionnaire-Short Form (IPAQ-SF) was used to evaluate participant physical activity. Results: Of the total cohort, 16.6% were diagnosed with constipation (13.6% males, 18.5% females). Logistic regression analysis showed a significantly greater risk of constipation in participants with female gender, advancing age, being obese. Participants who were moderately active (OR: 0.77, 95% CI: 0.62-0.91) and active (OR: 0.74, 95% CI: 0.59-0.90) had a decreased likelihood of constipation, when compared with inactive participants (p < 0.05). Participants in the middle upper quartile for water intake (OR: 0.71, 95% CI: 0.57-0.88), had a decreased likelihood of constipation, when compared with participants in the lowest quartile. Participants in the middle upper quartile (OR: 0.74, 95% CI: 0.58-0.92) and the highest quartile for dietary fiber intake (OR: 0.66, 95% CI: 0.52-0.84), had a decreased likelihood of constipation, when compared with participants in the lowest quartile (p < 0.05). Conclusion: Constipation is common in the Turkish adult population. Insufficient physical activity, decreasing fiber and water intake, obesity, advancing age and female gender were associated with increased constipation risks. Combining regular physical activity and increasing fiber and water intake may protect from constipation, and relieve constipation symptoms.