We sought to evaluate the association between sexual dysfunction and chronic retention of foreign bodies in the lower urinary tract (LUT) for long-term periods (≧4 weeks) in patients seen at three medical centres between January 2015 and September 2020, followed by assessing the impact of long-term retention of a foreign body in the LUT on sexual function. Thirty-eight patients were studied in the long-term group, among whom the aetiology of the foreign bodies included sexual desire with masturbation (n = 22, 58%), sexual inquisitiveness (n = 10, 26%), dysuria (n = 3, 8%) and seeking to relieve itching (n = 3, 8%). There were various types of foreign bodies, including a string of magnetic beads (n = 13), a thermometer (n = 5), plastic electric wire (n = 5) and others (n = 15). All cases presented with sexual dysfunction and LUT symptoms. Three months after foreign body removal, sexual dysfunction symptoms were significantly improved in 22 male cases and seven female cases. We found that chronic retention of foreign bodies in the LUT causes sexual dysfunction in both men and women. The psychological effects of fear may prevent these patients from seeking medical help. Thus, education on sexual medicine and timely removal of foreign bodies is necessary to avert sexual dysfunction and urinary tract infection.