SPERM transport through the female reproductive tract has been studied extensively in mammals1,2, but no systematic evaluation of the motility of spermatozoa at different levels of the tract after coitus has been reported. We describe a procedure for collecting oviducal spermatozoa and present observations on an unexpected reduction in the proportion of motile spermatozoa in the isthmus of the rabbit oviduct over the 12-h interval between mating and fertilisation.