Sera from 58 cases of confirmed human trichinosis were examined over an 11-month period. The enzyme-linked immunosorbent assay (ELISA) was used for the detection of class-specific serum antibodies (IgG, IgM, IgA, IgE) and for total serum IgE. The indirect immunofluorescent test served as reference technique. The ELISA proved to be more sensitive. Specific IgG antibodies were detected by ELISA in 100% of the clinical cases. Both IgG and IgM were demonstrable throughout the observation period of 11 months. Specific serum IgA was seen in 62% of the patients during the first 3 months, presumably the result of stimulation of the immune system by the adult worms in the intestine. Specific serum IgE was seen in a few cases only at the onset of the disease. Total serum IgE levels were elevated in 32% of the patients in the first month of the disease and in 17% after 11 months, compared to 10% of healthy individuals.