Neuronal growth factor (NGF) induces neurodifferentiation of PC12 cells into cholinergic neurons-like cells. It was shown that intracellular Ca2+ ions participate in regulation of the differentiation of PC12 cells. We tested whether L-type calcium channels contribute to Ca2+ entry which supports neurite outgrowth accompanying NGF-activated differentiation process. Development of morphological changes did correlate with increase of functional expression of L-type calcium channels. However, inhibition of L-type calcium channels by 1 μM of isradipine did not affect significantly an NGF-activated neurite outgrowth.