Toxoplasmosis is a parasitic infection whose clinical presentations depend on the human’s immune response. They can range from asymptomatic to rapidly progressive and deadly. There are no data on this disease in our population. Therefore, we have proposed to know the seroprevalence of toxoplasmosis in population risk groups through a descriptive, exploratory study in the 3 most populated districts of the province of Huancayo. The samples were processed by ELISA method and there were a total of 169 samples, 85 pregnant women and 84 cancer patients. The seroprevalence found in pregnant women was 44.7% and in cancer patients it was 26.2%. Finally, the only risk factor associated with positive serology was the place of origin, having a higher risk for those living in the district of Huancayo and Chilca compared to El Tambo (p < 0.05).