Swines with cysticercosis are a useful model to study human disease. A multidisciplinary approach was undertaken to study in detail the effect of praziquantel treatment on hosts and parasites. Computerised tomographic scans showed changes in the number and size of parasites in treated pigs. These changes were more apparent in muscle than in brain cysticerci. Neurophysiologic data were normal in cysticercotic pigs before and after drug treatment. An increase in antibody response was seen immediately after treatment regarding the amount of antibodies and number of antigens recognised. A lower number of polyploid lymphocytes was seen after treatment in cysticercotic pigs as compared to untreated pigs. At different times after treatment pigs were humanely euthanised. Oxygen consumption rate of cysticerci decreased after treatment and evagination was abolished. The inflammatory reaction that surrounded parasites increased in number and type of cells. This was more apparent around cysticerci obtained from muscle than from the brain.