We report four cases of femoral palsy due to compressive fibrosis, after pelvic radiation therapy. Three patients had Hodgkin's disease, and one testicular seminoma. Prominent clinical features include major groin induration and underlying swelling. Unlike what is usually seen in tumor relapse, little or no pain is associated with these neuropathies. The femoral post-radiation palsy develops earlier and faster than brachial plexus palsy of same aetiology. In one case, progressive aggravation led to surgical neurolysis which resulted in dramatic and long lasting improvement. The principal preventive and therapeutic managements are discussed: since compressive fibrosis is related to the use of isolated and massive electron beam therapy, various association of cobalt and electron beam therapy are designed to best prevent the side effects of each of these methods. The early treatment of developing fibrosis by D. penicillamine is discussed.