Trefoil factor family (TFF) peptides, besides their prominent expression in mucous epithelia, are also synthesized in the central nervous system. Previously TFF1 expression was observed in mouse brain astrocytes, while oxytocinergic neurons of the hypothalamo-pituitary axis are recognized sites of TFF3 synthesis. Here, the expression of TFF1, TFF2, and TFF3 was systematically studied using reverse transcription-polymerase chain reaction (RT-PCR) analysis of dissected adult mouse brain regions including the pituitary. Additionally, the developmental profile of TFF expression in murine cerebral cortex and cerebellum was monitored. Overall, the expression patterns of the three TFF genes differed. The TFF1 and TFF2 profiles shared some similarities, whereas the TFF3 expression pattern was completely different. TFF1 was nearly uniformly, but weakly expressed in all brain regions tested. The TFF1 and TFF2 expression patterns differed characteristically in the pituitary where abundant TFF2 transcription was detected in the anterior and not the posterior lobe and the expression level in males was higher than in females. In contrast, TFF3 expression was limited to the hippocampus, the temporal cortex, and the cerebellum, the latter being surprisingly the major site of expression. Here, TFF3 mRNA appeared to be restricted mainly to neurons and not glial cells. Cerebellar TFF3 expression is clearly developmentally regulated (maximum at P15), indicating a role for TFF3 during postnatal cerebellar development.