OBJECTIVES To evaluate the incidence of minor complications that rarely need treatment (haematuria, hematospermia and rectal bleeding) and major complications (fever and shock) in patients undergoing transrectal biopsy of the prostate and to identify risk factors. PATIENTS AND METHODS We present an analytic and prospective study where we evaluated 146 patients subjected to transrectal biopsy of the prostate from December 2007 to September 2008. Complications rates and variables were analyzed. RESULTS Eight patients (5,5%) suffered fever and seven (4,8%) of them were admitted. One of the patients (0,7%) suffered shock. The median of time between biopsy and fever was 3.5 days (1-10 days). Haematuria and hematospermia were more frequent in patients younger than 65 years (p<0.05) and fever and sepsis were more frequent in patients with prostate volume smaller than 55mL (p<0.05). CONCLUSIONS The complications of the transrectal biopsy of the prostate are frequent, autolimited and they rarely suppose a health hazard for the patients. The most frequent are haematuria and hemospermia, specially in younger patients, whereas infectious complications are rarer and in our study are more frequent in patients with smaller prostates. We must take into account that the information to the patient is very important after a prostate biopsy, so we can avoid useless consultations (for example with haematuria) and it will enable to identify important signs like fever earlier.