A woman initially aged 25 was treated for seven years for symptomatic vaginal trichomoniasis. Throughout that period the patient received 5-nitroimidazoles at conventional and high dosages, antimicrobial agents to eliminate vaginal organisms capable of interfering with treatment, acidifying preparations, and vaccination with inactivated Lactobacillus acidophilus. Despite all the regimens used, the condition remained refractory to treatment.