Background: Intravenous cannulation usage is a vital component for the patient admitted at hospitals . PIC insertion associated with some complications ranging from minor pain to severe thrombophlebitis and catheter related infections .The prevalence of thrombophlebitis due to IV insertion ranges fro 50-70%.In the present setting this sort of study is not yet conducted. Aims and Objective: To evaluate the effectiveness of application of topical heparin before peripheral venous cannulation with non application of heparin gel in prevention of thrombophlebitis at different intervals in patients undergoing intravenous cannulation in patients admitted in a tertiary hospital in Mumbai. Materials & Methods : A prospective, randomized, parallel group, single centre, clinical study .Main study was conducted after pilot study after obtaining clearance from ethical committee and consent from individual participants. A total 60 patients undergoing intravenous cannulation that has been planned to remain in situ for at least 72 hours indoor period were enrolled & randomized using computer generated random number table. Patients were randomized into Control vs Experimental group and assessed using a Visual Infusion Phlebitis Scoring Tool. Heparin gel was applied 5 minute before the procedure of intravenous catheter insertion at catheter site. Patients were evaluated using standardized tool Visual Infusion Phlebitis Score Tool for incidences of infusion phlebitis, first signs of phlebitis and treatment emergent application site reactions at 0.12,24,72 hours. Findings were statistically analysed for statistical significance, p - value below 0.05 levels was considered to be significant. Results: Application of topical heparin in the experimental group is effective in preventing and mitigating superficial thrombophlebitis compared to control group.At 72 hours the experimental group has a median superficial thrombophlebitis grade of 1 with an IQR of 1 whereas in control group has a median Superficial Thrombophlebitis grade of 4 with IQR of 1 indicating severe superficial thrombophlebitis at p value of < 0.001 Conclusion: Heparin gel application was effective in the prevention of infusion-associated phlebitis