The present study investigated the transfer of induced happy and sad mood functions through equivalence relations. Sixteen subjects participated in a combined equivalence and mood induction procedure. In Phase 1, all subjects were trained in 2 conditional discriminations using a matching-to-sample format (i.e., A1-B1, A2-B2, A1-C1, A2-C2). In Phase 2, they were tested for the formation of symmetry (i.e., B1-A1, B2-A2, C1-A1, C2-A2), and equivalence relations (i.e., B1-C1, B2-C2, C1-B1, C2-B2). In Phase 3, a musical mood induction procedure was employed to induce happy and sad mood states in the presence of the B stimuli. Eight subjects were exposed to happy music in the presence of B1, and sad music in the presence of B2, and for the other 8 subjects, this mood induction was reversed. In Phase 4, subjects were exposed to a mood functions test to determine whether the appropriate mood functions had been established with the B stimuli. In Phase 5, they were exposed to a transfer of mood functions test to determine whether the appropriate happy and sad mood functions had transferred via equivalence from the B stimuli to the C stimuli. The mood measures showed that the specific mood functions established in the presence of the B stimuli successfully transferred to the C stimuli for the majority of subjects. This transfer of mood function effect is discussed in terms of its implications for a behavioral understanding of mood changes. (Contains 6 figures.)