Introduction: In the first months of 2018, there was an increase in the number of cases of fever possibly related to toxoplasmosis in the city of Santa Maria, Brazil, reaching significant values. Toxoplasmosis is an autoimmune acute infection usually asymptomatic in 80-90% of immunocompetent adults. In this outbreak, the intensity of the symptoms presented warrants attention. Objective: To report cases of the toxoplasmosis outbreak in the city of Santa Maria, Brazil. Methods: This is a cross-sectional study using data on the outbreak of toxoplasmosis in Santa Maria published in bulletins by the Municipal Health Department of Santa Maria, Rio Grande do Sul, Brazil. Results: The outbreak of toxoplasmosis in Santa Maria was confirmed on April 19, 2018. Until June 14, 2018, 510 cases were confirmed. According to the most recent bulletin released by the State Health Department on June 8, 2018, 441 occurrences are people residing in Santa Maria. Five are residents of the districts and seven cases are patients residing in neighboring counties. In a bulletin published on May 25, 2018, 1,116 cases were reported to state epidemiological surveillance by the end of May. Of these, 766 cases were still suspected (fever, headache and/or myalgia accompanied by lymphadenopathy, weakness, arthralgia, or change in vision. In the other 460 cases, there was laboratory confirmation of acute toxoplasmosis, of which 35 were pregnant, with two fetal deaths (36 and 28 weeks), and two abortions. There are also 212 cases still pending laboratory confirmation. Discussion: The results of this research show that the current outbreak of toxoplasmosis in the city of Santa Maria, Brazil, is the largest reported in Brazil and appears to be the largest in the world. The notification to authorities by physicians was very important for the identification of this outbreak.