The findings of a seroepidemiological study into the prevalence of Toxoplasma gondii infection amongst normal blood donors and patients infected with HIV (human immunodeficiency virus) are presented. Of the total 301 participants, 181 were HIV antibody positive and 120 blood donors were HIV antibody negative. We used a prevalidated questionnaire, enzyme-linked immunosorbent assay (ELISA) and the Epi Info version 3.2 software plus SPSS version 10 for data analysis. The results showed an overall antibody prevalence rate of 53% in the population and a significantly higher infection rate amongst HIV-positive patients: odds ratio 2.14 (95% CI 1.30-3.53), p = 0.001. The study further showed that exposure to cats and highlands origin were independent risk factors. This study has demonstrated that in light of the current HIV/AIDS (acquired immune deficiency syndrome) epidemic, opportunistic infections such as toxoplasmosis will be a cause of considerable morbidity and mortality. It is therefore important that clinicians and public health practitioners fit these findings into overall management strategies to help control toxoplasmosis.