Taurine is a sulphur-containing amino acid with multiple functions, including cell protection. In the present work we studied the possible neuroprotective effect of taurine on ethanol-induced apoptosis in 7-day-old male mice whose cerebella are extremely sensitive to ethanol during synaptogenesis. The degree of apoptosis was estimated with immunostaining for activated caspase-3 in mid-sagittal paraffin-embedded sections containing lobules II-X of the cerebellum. Eight hours after ethanol administration (total dose 5 g/kg) the number of activated caspase-3-immunoreactive neurons was increased in the external and internal granular layers of all cerebellar lobules, indicating ethanol-triggered apoptotic neurodegeneration. Taurine treatment (two injections per 1 g/kg each) significantly decreased the number of activated caspase-3-immunoreactive cells in both external and internal granular layers after ethanol administration but its effect varied in different lobules. We conclude that taurine protects immature cerebellar neurons, reducing markedly ethanol-induced caspase-3 activation but does not abolish it completely. This study was supported by the Center for International Mobility (grants EH-04-2615 and MK-05-3550), the competitive research funding of Pirkanmaa Hospital District (grants 9F070, 9G051, 9G203) and the Finnish Cultural Foundation (2007).