The authors present the results of survey to detect anti-Toxoplasma gondii antibodies in 183 sera samples from donors in five blood banks in Natal -- Rio Grande do Norte, Brazil, through indirect immunofluorescence test. In this survey 151 reactive cases were found, starting with the titer of 1:16, in a rate of 82,5%. Considering as valid dilutions only titers equal or superior to 1:256, the rate found is of 43.7%. The higher titer found was 1:16.000 (1.3%). In the examined cases, the minimal age was 17 and maximal, 58. The age of most donors (91 cases) ranged from 21 to 30 years. Comparative studies were carried out with similar inquiries performed in other regions.