The elderly population, accounting for approximately 10.2% of the total population in 2008, has been on a steady rise. The growing elderly population results in a corresponding increase in the number of elderly patients suffering mobility impairment or chronic illnesses which in turn props up the demand for urinary catheterization. Purple urine bag syndrome (PUBS) is an uncommon and sporadical phenomenon, mainly found in chronically catheterized and constipated, debilitated women and related to urinary tract infection induced by bacteria with indoxyl sulphatase/phosphatase. The purple urine is a mixture of indirubin and indigo. This phenomenon is usually asymptomatic and requires no aggressive treatment but careful maintenance of a good hygiene of urinary tract and regular change of urinary catheter.