&NA;Sixty strips of vaginal wall obtained from 20 nonpregnant women (12 in the proliferative phase and 8 in the secretory phase of the menstrual cycle) were studiedin vitro.Described and illustrated are 1) their spontaneous contractility, 2) enhancement of this by prostaglandin F2&agr;, epinephrine, and norepinephrine, and 3)de novoinduction of contractions by these agents. Contractility was inhibited and suppressed by prostaglandin E&agr;, and after such suppression of norepinephrine‐induced contractions they could not thereafter be reestablished by norepinephrine. The physiologic implications of these findings for the processes of reproduction are discussed.