Background: Functional outcome of inltration of autologus platelet rich plasma (PRP) in delayed union of long bones. Prospective clinical study with 6 months of follow-up. Clinically proven Designe: Methods: 25 patients of delayed union were included in this study according to inclusion and exclusion criteria after getting written and informed consent, treated by autologous PRP inltration thrice 1 weeks apart, evaluation done clinically as well as radiologically. Out of twenty ve patients, union was achieved in 21 patients (84%) at Results: the end of six months, 4 cases progressed to non-union.The mean time between PRP injection & Union was 12.2 weeks. Final assessment was done according to RUS score at 6 months of follow-up Most of the patients 72% (18 patients) were in Excellent category, 12% (3 patients) were in Fair category and 16% (4 patient) was in poor category. Conclusion: Autologus Platelet rich plasma inltration locally is effective method in the treatment of delayed union of long bone fractures.