Background: Fracture healing is a complex biological phenomenon which is influenced by various environmental factors. From time immemorial, there has been a constant endeavor to look for means to enhance fracture healing which would limit disability and restore preinjury level of function at the earliest. Hyperbaric oxygen therapy is one such therapy which has shown some role in enhancing fracture healing in established fracture nonunion but its role in acute fracture healing has not been studied. Materials and Methods: The study was conducted in a military hyperbaric oxygen therapy (HBOT) facility co-located with a tertiary care military hospital. Sixty patients between 20 and 50 years of age with acute closed fractures of the metacarpal, planned to be managed conservatively, were equally randomized to the HBOT (n = 30) and sham HBOT (n = 30) group. Patients in the sham HBOT group, apart from receiving standard of care for the fracture, received a sham exposure of HBOT for 4 weeks, whereas those in the HBOT group, received HBOT therapy for the same duration. The patients were actively followed up for 6 months. Primary outcome measure was rate of fracture healing as assessed by radiology and ultrasound evaluation and functional recovery as assessed by the disabilities of the arm, shoulder, and hand score (DASH). Secondary outcomes included the assessment quality of life and complication rate. Results: The 6-month follow-up rate was 100%. All fractures in both the groups united, there was no significant difference in rate of fracture healing at 12 weeks (P = 0.731) or functional outcome at 24 weeks, as assessed by DASH score (P = 0.127), between the groups. There were 6 (20%) malunions in sham HBOT group and 2 (07%) in HBOT group. There were four cases of reflex sympathetic dystrophy in sham HBOT group and three cases in HBOT group. Conclusions: HBOT in acute diaphyseal fractures does not alter the rate of healing when assessed clinicoradiologically and has no effect on functional outcome at 6 months of follow-up. Level of Evidence: Level I