The development of the cerebral cortex depends on genetic factors and early electrical activity patterns that form immature neuronal networks. Subplate neurons (SPn) play a critical role in thalamocortical innervation, generation of oscillatory network activity and in the proper formation of the cortical columnar architecture. As glycine receptors play an important role during early corticogenesis, we analyzed the functional consequences of glycine receptor activation in visually identified SPn in neocortical slices from postnatal day 0-4 rats using whole-cell and perforated patch-clamp recordings. In all SPn the glycinergic agonists glycine, β-alanine and taurine induced dose-dependent inward currents with the affinity for glycine being higher than for β-alanine and taurine. Glycine-induced responses were blocked by the glycinergic antagonist strychnine, but were unaffected by either the GABAergic antagonist gabazine, the NMDA receptor antagonist APV or picrotoxin and cyanotriphenylborate, antagonists of -homomeric and 1 subunit-containing glycine receptors, respectively. Under perforated-patch conditions, glycine induced membrane depolarizations that were sufficient to trigger action potentials in most cells. Furthermore, glycine and taurine decreased the injection currents as well as the synaptic stimulation strength required to elicit action potentials, indicating that glycine receptors have a consistent excitatory effect on SPn. Inhibition of taurine transport and application of hypoosmolar solutions induced strychnine sensitive inward currents, suggesting that taurine can act as possible endogenous agonist on SPn. In summary, these results demonstrate that SPn express glycine receptors that mediate robust excitatory membrane responses during early postnatal development.