The pathomorphological effects of daily and weekly doses of liposomized albendazole on Trichinella spiralis larvae have been examined and compared during the course of muscle infections in mice. Treatment with three and six daily doses of the drug given by intraperitoneal injection to mice resulted in marked pathological alterations to encapsulated larvae, mainly in the walls of the capsules. There was a 5% efficacy against T. spiralis in mice given three daily doses of albendazole, and 38% efficacy in mice given six daily doses of the drug. The same doses of drug, when administered weekly, did not reduce the numbers of parasite larvae, and the application of drug at 6-weekly intervals resulted in a 5% reduction in numbers.