Abstract : Sexual behavior is one of the factors thought to be associated with Toxoplasma gondii infection. Several studies have shown that sexual behavior such as oral sex, a history of injuries to the genital organs during sexual intercourse, and working as a sex worker, is associated with Toxoplasma gondii infection. In addition, a history of injecting narcotic use is also associated with Toxoplasma gondii infection. One method to determine infection status is the serological examination through the measurement of immunoglobulin G (IgG). IgG seropositivity is the basis for determining the status of Toxoplasma gondii infection in the chronic or latent phase. This study aims to determine the relationship between sexual behavior and a history of injecting drug use with Toxoplasma gondii infection based on IgG serological status. This study's population was 62 Human Immunodeficiency Virus patients in DKI Jakarta, Bogor Regency and City, and Depok City. In this study, the infection status of Toxoplasma gondii was measured by ELISA method at the Department of Parasitology, Faculty of Medicine, and University of Indonesia. Sexual behavior and history of injection drug use were measured using a questionnaire. The results showed that 43 samples had positive serology status, 18 had negative serology status, and 1 was in the borderline range. Based on the analysis using logistic regression test, age, education, getting paid for having sex, using condoms during oral sex, the habit of swallowing ejaculated fluid during oral sex, history of injuries to the genital organs during sex, and history of injection drug use are factors Risk of Toxoplasma gondii infection.