The postcapillary venule is known to be the preferred site of lymphocyte migration into the extravascular compartment. In this study, induction of these high endothelial venule (HEV)-like vessels has been investigated by inoculation of live cytomegalovirus or inactivated virus into scala tympani of guinea pig cochleas. Endothelial cells of the spiral modiolar vein (SMV) were evaluated histologically 2 to 6 days following inoculation. The experimental group endothelial cells had larger nuclei and increased amounts of cytoplasm. In addition, many lymphocytes were adherent to and present within the vascular wall. Control SMV endothelia showed normal structure and morphology throughout the study. These findings reiterate that nonlymphoid tissues may develop HEV-like characteristics and suggest that HEV-like morphology may be acquired during an acute inflammatory condition in the cochlea.