Eleven patients who had undergone surgical treatment for head and neck cancer and had titanium implants placed for skin-penetrating prostheses were irradiated postimplantation. The absorbed doses of irradiation to the implant region varied between 50 and 80 Gy. The time interval between implant surgery and irradiation varied from 4 to 60 months. Of 32 fixtures placed, 2 were removed as part of extended tumor surgery and 2 were lost in conjunction with induced chemotherapy. Five of the patients showed skin dehiscences around 9 implants after completed irradiation. Osteoradionecrosis developed in three of the patients after radiotherapy. If irradiation is to be performed in areas where titanium implants have been placed, it is recommended that all prostheses, frameworks, and abutments be removed before irradiation; the fixtures should be allowed to remain intact but should be covered with skin or mucosa. Keywords: backscatter effects, irradiation, osseointegration, prosthetic reconstruction, titanium implants