Background: Supracondylar fracture of humerus in children constitutes more than half of paediatric elbow injuries requiring hospitalisation. Data over outcomes of delayed surgery in Gartland type III fracture supracondylar humerus in children is scarce and no clear guildelines exist regarding management of such injuries. Hence, we envisaged to study the functional and radiological outcome and complications of delayed surgery (between 2-12 days) in paediatric patients with Gartland type III supracondylar fracture of humerus. Material and Methods: A prospective interventional study was conducted in 20 patients aged 4-12 years presenting in Orthopaedic OPD / emergency with Gartland type III fracture supracondylar humerus without associated neurovascular compromise and without other injuries who underwent delayed open reduction and cross K wire fixation through medio-lateral approach. At latest follow up (min 3 months), functional outcome was assessed using Flynn's criteria which includes loss in range of motion (ROM) and loss of carrying angle. Radiological outcomes were assessed using Baumann's angle and anterior humeral line. Complications, if any will be noted. Results: Mean age was 7.75 ± 2.38 years (4-12 years) and mean delay in surgery was of 3.9 ± 1.65 days (2-9 days). Out of 20 patients, right sided extremity was involved in six (20%) patients while 14 (70%) patients suffered injury over left side. The minimum follow up period was of three months with a mean follow up of 5.54 ± 0.72 months. The mean loss in ROM was 21.2⁰ ± 13.5⁰ (5⁰-55⁰) at three on this and 12.4⁰ ± 8.8⁰ (0⁰-30⁰) at six months. The difference was found to be statistically significant (p-value˂0.05). The mean loss of carrying angle was 8.1⁰ ± 6.21⁰ (1⁰-22⁰) at three months and was 4.58⁰ ± 5.65⁰ (0⁰-20⁰) at six months of follow up which was found to be statistically significant (p-value˂0.005). As per Flynn's criteria, functional outcome was found to be satisfactory in seven (35%) patients and unsatisfactory in 13 (65%) patients at three months follow up. Twelve patients reached six months follow up period, seven (58.3%) patients had satisfactory outcome while five (41.7%) patients had unsatisfactory outcome. Difference in Baumann's angle was found to be statistically insignificant when compared with immediate postop and latest follow up (min three months). During immediate postop anterior humeral line passed through capitellum in 90% patients and anterior to capitellum in 10% cases. At latest follow up, it passed through capitellum in 85% cases and anterior to capitellum in 15% cases. Postop serous blisters and pin site infection each was found in one (5%) patient while cubitus varus was found in four (20%) patients. Conclusion: At three months follow up, we achieved satisfactory results in some patients but with continued physiotherapy we were able to achieve satisfactory results in significant proportion of patients at six months follow up. So open reduction with K wire fixation is a reasonably fair method for tackling delayed presenting Ga...