Objective : To study the efficacy of yoga on Guna (yogic personality measure) and general health in normal adults. Methods : Of the 1228 persons who attended introductory lectures, 226 subjects aged 18-71 years, of both sexes, who satisfied the inclusion and exclusion criteria and who consented to participate in the study were randomly allocated into two groups. The Yoga(Y) group practised an integrated yoga module that included asanas , pranayama , meditation, notional correction and devotional sessions. The control group practised mild to moderate physical exercises (PE). Both groups had supervised practice sessions (by trained experts) for one hour daily, six days a week for eight weeks. Guna (yogic personality) was assessed before and after eight weeks using the self-administered Vedic Personality Inventory (VPI) which assesses Sattva (gentle and controlled), Rajas (violent and uncontrolled) and Tamas (dull and uncontrolled). The general health status (total health), which includes four domains namely somatic symptoms (SS), anxiety and insomnia (AI), social dysfunction (SF) and severe depression (SP), was assessed using a General Health Questionnaire (GHQ). Results : Baseline scores for all the domains for both the groups did not differ significantly ( P > 0.05, independent samples t test). Sattva showed a significant difference within the groups and the effect size was more in the Y than in the PE group. Rajas showed a significant decrease within and between the groups with a higher effect size in the PE group. Tamas showed significant reduction within the PE group only. The GHQ revealed that there was significant decrease in SS, AI, SF and SP in both Y and PE groups (Wilcoxcon Singed Rank t test). SS showed a significant difference between the groups (Mann Whitney U Test). Conclusions : There was an improvement in Sattva in both the Yoga and control groups with a trend of higher effect size in Yoga; Rajas reduced in both but significantly better in PE than in Yoga and Tamas reduced in PE. The general health status improved in both the Yoga and control groups.