Background. Immediate breast reconstruction techniques include tissue-expansion, latissimus dorsi flap with or without an implant, pedicled TRAM flap and free tissue-transfer. Adjuvant radiotherapy decreases loco-regional recurrence and increases overall survival. Radiotherapy in the presence of a tissue-expander or an implant can lead to an increased number of complications and poor cosmetic outcome.Aim of the study. To study the relationship between radiotherapy and the choice of the immediate breast reconstruction technique in view of the increased number of breast cancer patients receiving adjuvant radiotherapy.Patients and methods. An audit of 121 patients who had immediate breast reconstruction over a period of 2 years was reviewed retrospectively. In March 1998, the radiotherapy protocol was revised. Forty-two patients operated on between January 1997 and March 1998 were compared to 79 patients operated on between April 1998 and June 1999.Results. The percentage of patients receiving adjuvant radiotherapy increased in the second period as well as the proportion of autologous breast reconstruction. A small percentage of patients required unexpected radiotherapy after insertion of tissue expanders, due to narrow excision margins or unexpected pathology. Only two patients had tissue-expansion although radiotherapy was likely.Conclusion. The choice of the immediate breast reconstruction technique was satisfactory in most patients. The use of implants is best avoided in patients who may require adjuvant radiotherapy. Autologous immediate breast reconstruction, either free or pedicled flaps, is a safer choice for those patients.