Background: Annually, India meets only half of its blood requirement and half of it from unsafe blood donors. There is a need to increase blood donations from safe and voluntary blood donors. Recruitment and retainment of voluntary blood donors are key challenges for blood agencies. Aim: The aim of this study is to assess the impact of mass counseling in the creation of voluntary blood donor. Subjects and Methods: Interventional study with intervention of mass counseling of relatives of patients admitted in the wards of Tertiary Care Hospital attached to medical college in Pune. It was carried out during 1st May 2010 to 31st May 2010. 110 relatives were randomly selected for the study. Mass counseling of cases regarding voluntary blood donation was carried out by trained persons. Pre‑counseling and post‑counseling knowledge, attitude, and behavior (KAB) scores regarding blood donation were assessed using a pre‑tested semi‑structured questionnaire. Results: Counseling improved knowledge, attitude and behavior score (KAB) regarding blood donation significantly. Pre‑counseling and post‑counseling KAB scores difference was statistically significant (P < 0.001) and was not merely by chance. Counseling helped to improve behavior of cases regarding blood donation, too. Conclusion: Continuous counseling sessions for blood donation may serve the purpose for institutes dealing with a large number of people every‑day. Establishment of mobile counseling units by blood banks may help to create a voluntary blood donor. Changes in motivation and the development of self‑identity as a blood donor are needed to retain voluntary blood donors. Incentive's offered for voluntary blood donation card should be strengthened.