Abstract: The frequency of Trichomonas vaginalis infection in HIV-positive and negative women attending hospitals in Goiania, Brazil was evaluated using the gold standard diagnostic method of culture. A total of 237 vaginal swab specimens were examined: 125 (52.7%) comprising the HIV-positive group and 112 (47.3%) the HIV-negative control group. T. vaginalis was detected in 13.5% of the women, 23 (18.4%) of whom were HIV-positive while 9 (8.0%) were HIV-negative. This difference was statistically significant however, infection by this parasite was not found to be associated with immune status. T. vaginalis was found in 23.1% of the pregnant women and there was a statistically significant difference in the rate of infection by this parasite between the pregnant HIV-positive and the pregnant HIV-negative women (25.8% versus 12.5%). T. vaginalis was more prevalent in HIV-positive compared to HIV-negative women however, no association was found between the infection and the immune status of the patients.