We examined the effects of normal and leucocyte-positive semen on cytokine expression in endometrial epithelial cell cultures. Cytokines in pooled seminal plasma (SP) samples of men with normal semen parameters without (n = 9) and with leucocytospermia (LCS) (n = 9) were determined. Cultures of epithelial endometrial cells of women (n = 7) in the secretory phase were incubated with 10% SP for 24 h. Cytokines in culture supernatants and mRNA concentrations in the cultured cells were determined. Mean concentrations of interleukin (IL)-1β and transforming growth factor (TGF)-β1 were significantly higher (P < 0.05) in culture media with SP of men with normal semen parameters and LCS compared with control. Accordingly, a significant increase (P < 0.05) in mRNA concentrations (amol ml−1) of IL-1β and TGF-β1 could be detected. The mean TGF-β1 and IL-1β concentrations in the culture supernatant with 10% SP from patients with normal semen parameters were 24-fold (P < 0.05) and 2-fold higher respectively when compared with control. The mean protein concentration of TGF-β1 measured in the supernatant with SP of men with LCS was not significantly reduced as compared with the supernatant with normal SP. In conclusion, our experiments support the concept of an endometrial sensitation effect by semen.