Objective: We sought to determine the clinical and laboratory features of trichomonas vaginitis (TV) in a chronic vaginitis clinic.Methods: We studied 45 women with symptomatic TV attending a specialty chronic vaginitis clinic. These patients were older than the usual symptomatic patients with TV. They frequently described unusual chronicity of symptoms, half being referred because of clinical resistance and the other half referred because of chronic vaginitis of unknown etiology.Results: In spite of the chronicity of infection, the signs and symptoms of florid inflammation were still evident and high numbers of polymorphonuclear leukocytes and parasitic load were present.Conclusions: A longstanding infection, especially if previously untreated, invariably responded to conventional nitroimidazole therapy. In addition, the majority of patients seen with clinical resistance to the conventional doses of metronidazole responded to high-dose oral metronidazole therapy. Unsuspected TV should always be considered in low-risk patients with chronic vulvovaginal symptoms.