To analyze our experience with the management of retroperitoneal abscesses. A retrospective study was made of 66 patients with retroperitoneal abscesses treated at our hospital from January 1975 to July 2001 for the purpose of analyzing the diagnosis and treatment of these rare infections. In each case, we analyzed patient characteristics, abscess location and origin, predisposing factors, clinical presentation, microbiology, radiographic findings, treatment, and outcome. In our series, the most frequent type of abscess was perinephric (45.4%), and the most frequent origin was the kidney (72.7%), generally renal lithiasis or previous urological surgery. Gram-negative bacilli were the microorganisms most often involved as causal agents of abscesses. CT had the best diagnostic performance (95%). Percutaneous drainage resolved the abscess in 86.3% of the patients in which it was used, compared with 87.5% for traditional surgical drainage. In 4 cases, the only treatment was administration of antibiotics. In all these cases the abscesses were smaller than 3 cm and patients were in good general condition. The mortality rate was excellent (1.5%), probably due to the low rate of comorbidity in our patients. Gram-negative bacilli were the most frequent microorganisms in our retroperitoneal abscesses. CT was the imaging technique that produced the most reliable and rapid diagnosis. Radiographically-guided percutaneous drainage was a safe and effective therapeutic alternative when used as definitive treatment or preoperatively.