Secretory immunoglobulin A (sIgA) measured in saliva, an index of mucosal immunity, has repeatedly been shown to be sensitive to psychological variables. Chronic stress is downregulatory whereas an acute psychological challenge induces mobilisation. We examined whether an acute manipulation of mood to induce negative hedonic tone would be downregulatory, as in the chronic stress paradigm and further, whether induction of positive mood might have opposite effects. Two separate experiments were conducted. In the first, mood manipulation was by mental recall and in the second by music. For both sIgA concentration and sIgA secretion rate there was a significant elevation in response to the mood manipulation by recall regardless of hedonic tone. There was some evidence that for sIgA secretion rate the response was more pronounced for positive mood. Mood induction by music also resulted in significant elevations in sIgA concentration and secretion rate and responses were not distinguished by mood valence. None of the mood induction procedures was associated with changes in free cortisol. In these studies, we found no evidence that transient lowering of mood was downregulatory for salivary sIgA. The predominant finding was of sIgA mobilisation.