The antibody response to Trypanosoma evansi antigens in rabbits experimentally infected with T. evansi was monitored by SDS-PAGE and “Western” blotting. As defined by the number of antigenic components recognised and the intensity with which they were labelled, responses were predominantly IgG, followed by IgM and IgA. During infection and subsequent drug treatment seven major antigenic components (94, 85, 75.5, 67, 60.5, 43, and 28.6 kDa) were identified by IgG. Antibodies to a 32.4 kDa and three other components (30, 28.6 and 12.5 kDa) appeared during infection and after chemotherapy respectively. Three components (94, 67 and 60.5 kDa) recognised by IgG were also detected by IgM and IgA. Furthermore, two bands (30 and 12.5 kDa) were identified by IgM and one (12.5 kDa) by IgA only after drug treatment, while a 28.6 kDa component was recognised by IgM and IgA during the same period. These findings constitute a basis for the exploration of class-specific antibody responses to T. evansi antigens with relevance to diagnosis, protection and pathology.