The author compares two types of Toxocara canis extracts and an Ascaris suum extract from the antigenic point of view. Double immunodiffusion (Ouchterlöny) was the method employed. The T. canis extract (Jeska, 1967) showed 7 bands against its homologous antiserum. The A. suum extract (Jeska, 1967) showed 3 bands against the same antiserum, one of them with partial identity with the previous antigen. The second type of T. canis antigen (Woodruff and Thacker, 1964) gave only 3 bands against this antiserum, and showed a total identity pattern with the other T. canis extract.