We report five cases of purple urine bag syndrome (PUBS). All the patients were women and they had been bed-ridden for a long period due to cerebrovascular diseases. They tended to be constipated as a result of habitual use of laxatives. Indicanuria was proven in the all urinary samples from the patients. The four assessable urinary cultures showed Proteus mirabilis contamination. Total days without evacuation per month in patients with PUBS and control subjects (5 catheterized subjects without PUBS) were 16.5 +/- 3.7 and 6.8 +/- 4.8, respectively (mean +/- SD), showing a significant difference (p < 0.05). In each case, this syndrome was not considered to have affected their clinical course. We concluded that it is unnecessary to treat patients with PUBS aggressively. Control of evacuation and urological sanitation are important in these patients.