The purpose of this study was to analyze the transrectal ultrasound (US), or TRUS, and color Doppler ultrasonography (CDU) findings and therapeutic strategies with TRUS-guided procedures in 13 patients with prostatic abscess. Over a period of 6 years, 18 prostatic abscesses were diagnosed in 13 patients (mean age: 59 years). Diagnostic workup included TRUS, analysis of midstream urine, and analysis and culture of abscess fluid for leukocytes and pathogens. These patients were treated either conservatively (for abscess cavities < 1 cm in diameter), or by aspiration or draining procedures (cavities > or = 1 cm). The transrectal CDU findings were correlated to the treatment effects. The predisposing factors were also reviewed. In the 13 patients, the most common clinical symptom and sign were urinary frequency (77%) and pus cell in the midstream urine (92%). Predisposing factors were found in 11 men, with diabetes in 5 of them. In 10 patients, the definitive preinterventional diagnosis was based on the TRUS findings. TRUS with probe palpation demonstrated tiny floating echogenic speckles in the abscess cavity in 4 patients. CDU demonstrated increased color-flow signals at the margin and surrounding tissue of the abscess pockets. Abscesses with poorly defined boundaries had more prominent surrounding color-flow signals and achieved, with relative difficulty, a satisfactory aspiration procedure. Aspiration was done for all 11 abscesses between 1 and 3 cm. A total of 4 larger abscesses (> 3.0 cm) were treated with aspiration or drainage using a 5-French pigtail catheter. No surgical drainage was performed. Transrectal CDU may help in the evaluation of maturity of an abscess pocket. US-guided aspiration with an 18-gauge needle or drainage with a 5-French pigtail catheter significantly shortened the hospital stay.