OBJECTIVES: Physical activity has a positive effect on people's mental health and well-being. The aim of this study was to compare the effects of hatha yoga and resistance exercises on mental health and well-being in sedentary adults. DESIGN: Randomized controlled study. METHODS: Fifty-one participants aged mean (SD) 25.6 (5.7) years were randomly divided into three groups: Hatha Yoga Group, Resistance Exercise Group and Control Group. The Hatha Yoga Group and Resistance Exercise Group participated in sessions three days per week for 7 weeks and the Control Group did not participate in any sessions. All the subjects were evaluated through the Rosenberg Self-Esteem Scale, Beck Depression Inventory, Body Cathexis Scale, Nottingham Health Profile and Visual Analog Scale for fatigue pre-and post-session. RESULTS: Significant improvements were found in terms of all outcome measures in the Hatha Yoga Group and the resistance exercise group. No improvements were found in the Control Group. Hatha yoga more improved the dimensions fatigue, self-esteem, and quality of life, whilst resistance exercise training more improved body image. Hatha yoga and resistance exercise decreased depression symptoms at a similar level. CONCLUSION: The results indicated that hatha yoga and resistance exercise had positive effects on mental health and well-being in sedentary adults. Hatha yoga and resistance exercise may affect different aspects of mental health and well-being.