The objective of this study was to investigate the effects of riboflavin-deficient and Trichinella spiralis-induced stresses on corticosterone associated with spermatogenesis in male Wistar rats. Rats were allocated into 4 groups: Group 1: control; group 2: riboflavin-deficient diet; group 3: T. spiralis infection; group 4: riboflavin deficient diet with T. spiralis infection. This experiment lasted for 12 weeks. Plasma corticosterone was significantly enhanced when exposed to acute riboflavin deficiency and/or T. spiralis infection stress. When the rats were chronically subjected to such stresses, T. spiralis per se had prolonged effects, in a marked increase in corticosterone. T. spiralis per se tended to impact on such sperm characteristics as sperm motility, sperm count and daily sperm production, even defected seminiferous tubules. It was proposed that the Trichinella spiralis-induced stress probably had adverse effects on the level of adrenocortical-testicular axis whenever their habitats on muscle fibers were evident. However, riboflavin-deficient-induced stress had little implication in the adrenocortical-testicular axis.