We undertook a prospective open, non-randomised study to determine the efficacy of out-patient treatment of postoperative superficial wound infection, in patients with orthopaedic implants using single daily IM injection of ceftriaxone and to examine the cost effectiveness when compared with inpatient management. The study comprised of 25 patients who have had primary total hip or knee replacements or Dynamic Hip Screw fixation for an intertrochantric fracture. The superficial wound infections were categorised into mild, moderate and severe according to the classification described in this article and the length of administration of antibiotic varied according to the severity of infection. There were no failures in the study. It was estimated that an overall cost savings of £33.840 could be achieved. We recommend that superficial wound infection in association with major orthopaedic operations using implants can be managed with ceftriaxone as an out-patient.