Various forms of synaptic plasticity underlying motor learning have already been well characterised at cerebellar parallel fibres (PFs)-Purkinje cells (PCs) synapses. As inhibitory interneurones play an important role in controlling the excitability and synchronisation of PCs, we tested the possibility that excitatory synapses between PFs and stellate cells (SCs) are also able to exhibit long-term changes in synaptic efficacy that might contribute to cerebellar network function. In the present study, we show that long-term potentiation (LTP) and long-term depression (LTD) were induced at these synapses by a low frequency stimulation protocol at 2 Hz for 60 s and that pairing this low frequency stimulation protocol with post-synaptic depolarisation induced a marked shift of synaptic plasticity in favour of LTP. This LTP was cAMP independent, but required nitric oxide (NO) production from pre- and/or post- synaptic elements, depending on the stimulation or pairing protocol used respectively. In contrast, LTD was not dependent on NO production but required activation of post-synaptic group II, and possibly also of group I metabotropic glutamate receptors. Finally, PFs stimulations at 8 Hz for 15 s also induced LTP at PF-SC synapses, but in this case, LTP was cAMP dependent, like pre-synaptic LTP induced in the same conditions at PF-PC synapses. Thus, long-term changes in synaptic efficacy can be accomplished by PF-SCs synapses, as well as by PF- PC synapses, so that both types of plasticity might co- operate during cerebellar motor learning.