The present study was planned to investigate sleep-prolonging effect of C. sativum. The hydro-alcoholic extract (HAE) and its three fractions namely water (WF), ethyl acetate (EAF) and N-butanol (NBF) were prepared from C. sativum aerial parts and administrated to mice. Also, the possible cytotoxicity of the extracts was tested using cultured PC12 cells. The HAE, EAF and NBF significantly prolonged sleep duration. Only the NBF could significantly decrease sleep latency. No decrease in the neuronal surviving was observed either by HAE or by its fractions. The present data indicate that C. sativum exert sleep-prolonging action without major neurotoxic effect.