Cervical tissue explants (CTEs) from 22 HIV-1 seronegative women were exposed to R5 HIV-1 ex vivo. Eight CTEs were productively infected in terms of HIV-1 p24 Gag release in culture supernatants, whereas 14 were not. Nonetheless, both accumulation of HIV-1 gag DNA and of p24 Gag+ CD4+ T cells and macrophages occurred in both productive and, at lower levels, in nonproductive CTEs. Nonproductive CTEs differed from productive CTEs for higher secretion of CC motif chemokine ligand 3 (CCL3) and CCL5. A post-hoc analysis revealed that all productive CTEs were established from women in their secretory phase of the menstrual cycle, whereas nonproductive CTEs were derived from women either in their secretory (28%) or proliferative (36%) menstrual cycle phases or with an atrophic endometrium (36%). Thus, our results support the epidemiological observation that sexual HIV-1 transmission from males to women as well as from women to men is more efficient during their secretory phase of the menstrual cycle.