Total knee arthroplasty is sometimes associated with excessive bleeding necessitating blood transfusion. Transfusion is associated with risk of disease transmission and immunological burden to the recipient. Material and methods: 100 patients undergoing primary total knee replacement were randomly allocated into 2 groups: a) immediate release of drain following release of tourniquet and b) delaying release of the clamp by one hour. Drains were removed at 48 hours post-op. Results:Average amount of postoperative bleeding in the immediate release group was 1050 ml (95% CI interval for mean 728 to 1172) compared to delayed release group of 732 ml (95% CI interval for mean 620 to 845). Applying Mann- Whitney U test p< 0.001 which was highly signiþcant. Corrected drop in Hb% at 48 hours showed an average difference of 0.17 gm% less drop in the delayed release group. 78 units were transfused in the immediate group compared to 66 units in the delayed group. There was no difference in parameters like length of stay (average 13 days in both groups), bruising around the knee, oozing or blister formation between the two groups. Three patients had DVT and 1 PE in the immediate release group, 2 cases of DVT in the delayed release group. One patient required MUA in the immediate release group compared to 3 in the delayed group. Conclusion:Our result conclusively shows that delaying release of drain by an hour can signiþcantly reduce blood loss. It is a simple method without any associated complications and can reduce transfusion requirements in patients undergoing knee replacement surgery.