Trichomoniasis is the most common non-viral sexually transmitted infection (STI), and it is caused by the protozoan flagellate Trichomonas vaginalis. T. vaginalis is strictly human pathogen that infects the urogenital tracts of men and woman, and it is transmitted from person to person via close contact of genital mucosa. The clinical manifestations od trichomoniasis differ and can vary from asymptomatic infection to unpleasantly symptomatic infection. T. vaginalis most commonly causes urethritis in men and vaginitis and cervicitis in women; however, infections are often asymptomatic. T. vaginalis infection in men is associated with balanoposthitis, prostatitis, epididymitis, penile superficial ulceration decreased sperm cell motility, and infertility. Trichomoniasis is also associated with increased HIV transmission. Epidemiologically, T. vaginalis infections are commonly associated with other STIs. The incidence of trichomoniasis exceeds rates for gonorrhoea and chlamydial infection combined. The estimated infection rates cited in the literature may indeed be too low because trichomoniasis is not a retortable disease in many countries; the infection, particuraly in men, can be asymptomatic; and laboratory tests used for diagnosis often have inappropriate sensitivity. Laboratory diagnostic tests can be classified into direct and indirect. Direct tests are: microscopy, cultivation, antigen detection tests, and molecular diagnostic techniques; whereas indirect tests are antibody detection tests. Systemic treatement with 5-nitroimidazoles is the corestone of management of trichomoniasis, and the recommended treatement for T. vaginalis infection is metronidazole or tinidazole.