In this prospective study, superficial and deep swabs of all open fractures seen at the accident and emergency unit of our hospital between January and June 2000 were taken (before wound debridement was done or anitibiotics commenced). Routine microscopy, culture and sensitivities for aerobic and anaerobic organisms were carried out on these specimens. The organisms were cultured and identified using standard techniques and the antibiotic sensitivity testing was carried out using the disc diffusion method of Stokes. Within six hours of injury, single-organism isolates were commonly found whilst after 48 hours a mixed or poly-microbial organism load were isolated. In 90% of the positive isolates, the organisms isolated form the superficial and the deep swabs were the same. The antibiotic sensitivity pattern of all the isolates shows that pefloxacin, ciprofloxacin and ceftriaxone were more effective compared to cefuroxime and amoxycillin which had substantial resistance to most of the isolates. 41 fractures were followed to union and 4 (9.7%) developed osteomyelitis.