We evaluated a prosthesis-retaining treatment protocol for prosthetic joint infection in patients presenting at a mean of 116 days (range 10-1216 days) after primary arthroplasty. Our regime involved irrigation and debridement followed by implantation of biodegradable gentamicin loaded sponges which do not require removal after implantation. Of 34 patients with a deep infection after total hip arthroplasty, Twenty-five were treated successfully, with a mean follow-up of 35 months. There were no permanent complications. This success rate is comparable to earlier studies. Early initiation of treatment demonstrated a tendency for better results, and late chronic infections had a worse outcome. Because the sponges are degradable, a number of further surgical procedures were avoided.