Objectives: To compare the cumulative effect of commonly practised slow and fast pranayama on cognitive functions in healthy volunteers. Settings and Design: 84 participants who were in self-reported good health, who were in the age group of 18-25 years, who were randomized to fast pranayama, slow pranayama and control group with 28 participants in each group. Material and Methods: Fast pranayama included kapalabhati, bhastrika and kukkuriya. Slow pranayama included nadishodhana, Pranav and Savitri. Respective pranayama training was given for 35 minutes, three times per week, for a duration of 12 weeks under the supervision of a certified yoga trainer. Parameters were recorded before and after 12 weeks of intervention: Perceived stress scale (PSS), BMI, waist to hip ratio and cognitive parameters-letter cancellation test, trail making tests A and B, forward and reverse digit spans and auditory and visual reaction times for red light and green light. Statistical Analysis: Inter-group comparison was done by one way ANOVA and intra-group comparison was done by paired t-test. Results and Conclusion' Executive functions, PSS and reaction time improved significantly in both fast and slow pranayama groups, except reverse digit span, which showed an improvement only in fast pranayama group. In addition, percentage reduction in reaction time was significantly more in the fast pranayama group as compared to that in slow pranayama group. Both types of pranayamas are beneficial for cognitive functions, but fast pranayama has additional effects on executive function of manipulation in auditory working memory, central neural processing and sensory-motor performance.