Parkin is an E3 ubiquitin ligase causally involved in the pathogenesis of autosomal recessive juvenile parkinsonism. In this paper, we analysed the formation of alternative splice products and the spatio-temporal expression pattern of parkin during pre- and postnatal mouse development. Using RT-PCR, Northern blot, in situ hybridization, Western blot analysis, and immunohistochemistry we found (i) alternative splice forms of parkin; (ii) an early and widespread expression of parkin mRNA and protein in the CNS and several organs, already at E10/12; (iii) a marked increase in expression level during midgestational development (E15-18) in the CNS, followed by a steady increase until adulthood; (iv) an ubiquitous distribution throughout CNS ontogeny. Our results show that parkin expression is correlated with cell maturation and suggests an important physiological role of parkin in neurons that is at no time limited to the dopaminergic system.