We performed this analysis to document the rate and severity of complications both during and after local field irradiation for localized prostate cancer and to assess the influence of three-dimensional conformal radiation therapy (3DCRT) on these complications. Bowel, urinary and cutaneous toxicities were noted in all patients treated with primary radiotherapy (RT) for prostate cancer using Radiation Therapy Oncology Group/European Organization for Research on Treatment of Cancer scores. Evaluations were performed weekly during RT, 6 weeks after RT and 3 monthly thereafter. Data on 111 were analysed. We also compared the complications of conventional and 3DCRT. The serious complication rates identified in this study compare favourably with those reported in the literature. Only 3.6%, 0.8% and 0% had acute grade 3 or 4 urinary, bowel or skin reactions respectively. Only two patients had chronic grade 3 or 4 urinary complications. Thus far no patients have developed chronic bowel or skin complications greater than grade 2. Despite dose escalation from 66 Gy to 70 Gy (with 3DCRT), there was a trend towards reduced toxicity when 3DCRT was compared with conventional radiation. RT is a well-tolerated treatment for early stage carcinoma of the prostate and our complication rates are compatible with international experiences. Further follow-up is required to determine the efficacy of treatment, the incidence of impotence and the final number of late complications.