Abstract: The inhibitory effect of methanolic extract of Asparagus pubescens Bak root was studied in rat and guinea pig uterine muscles, respectively. The extract caused a concentration dependent decrease in frequency and amplitude of spontaneous activity in rat uterine muscle. It also caused a significant (p< 0.05-0.001) dose-dependent decrease in acetylcholine-induced contraction in guinea pig uterine muscle. The sensitization of the tissue caused by 8.0x10-6 g mL-1 of extract accentuated with 1.6x10-5 g mL-1 was blocked by verapamil, an extracellular calcium antagonist. The extract dose-dependently also inhibited Ach-induced contraction in Ca2+ free Physiological Salt Solution (PSS). This inhibition which was statistically significant (p< 0.05-0.001) was substantially reversed by addition of extracellular calcium. This inhibitory effect may in part involve the interference with intracellular/extracellular calcium mobilization.