Previous investigations of the influence of exogenous progesterone on the rate of egg transport through the rabbit oviduct have yielded some conflicting data. This study was designed to measure the effects of exogenous progesterone on tubal ovum passage, and to examine possible interaction between alpha adrenergic receptors and progesterone. Groups of New Zealand does were given progesterone for 3 days prior to ovulation, or on the day of ovulation and the 2 following days. Some groups were treated with phenoxybenzamine in doses sufficient to induce alpha adrenergic blockade. Progesterone given prior to ovulation accelerated ovum transport through the oviduct. When given after ovulation, progesterone did not increase the rate of transport of eggs through the oviduct. Phenoxybenzamine treatment did not alter the changes in rate of egg transport induced by progesterone.