From July 1990 to September 1992, 32 elderly male patients with benign prostatic hypertrophy complaining of chronic urinary retention were treated with polyurethane intraurethral catheters (IUC). All of them were unfit for prostatic surgery due to several complications. Indwelling lUCs were left for more than 6 months in 20 (62.5%) patients, and the longest period was 1 year and 11 months. Indwelling lUCs could not be used in patients who had undergone previous operations for prostatic hypertrophy. Comparing urodynamic study findings prior to and after insertion of the IUC results in patients with an overactive or normal bladder were significantly better than those in patients with an underactive bladder (p<0.05, chi-square test). Nine patients were urine continent, and 2 of those patients in whom an indwelling IUC could be left for more than 6 months, complained of mild urinary incontinence. Urinary tract infection disappeared in 7 patients, and improved in 11 of the 20 patients. IUC placement was successful for more than 6 months without exchange in 7 of the 20 patients. Bladder stone formation was found in one patient and was the only complication in these 20 patients. In conclusion, IUC placement can be successful for more than 6 months in patients without underactive bladder or previous prostatic operation.