Exogenous hormones used for controlled breeding purposes are commonplace in the Australian sheep industry. However, their use has been linked to increased cervicovaginal mucus production, reduced sperm migration through the female tract and altered fertility. The aim of this study was to investigate the effect of hormonal synchronization and/or superovulation on the ability of frozen-thawed spermatozoa to penetrate ovine cervicovaginal mucus. Mucus was collected from naturally cycling (Nat), progesterone synchronised (P₄) and superovulated (SOV) mature Merino ewes (n=22 ewes/treatment) via aspiration from the cervicovaginal region twice during oestrus.  Oestrus was determined by analysis of circulating progesterone and oestrogen levels and harnessed androgenised wethers. Mucus samples were aspirated into flat glass capillary tubes, incubated (1h) with frozen-thawed ram spermatozoa (20 x 10⁶ motile spermatozoa/ml), then assessed for numbers of spermatozoa which had penetrated 1cm. pH of cervicovaginal and cervical mucus was assessed in vivo at the time of collection via a portable pH probe.  Spermatozoa travelled further in the mucus of SOV ewes compared to Nat and P₄, but differences were not significant (p>0.05). Mucus pH did not differ significantly between collection sites nor was it altered by hormonal synchronisation or superovulation (p>0.05), with an average pH of 6.4. Significant variation in mucus penetration within and between samples of the same treatment was observed. These results suggest sperm migration through a given volume of mucus is not affected by common hormonal artificial breeding treatments, although the large variation observed in sample volume and penetration within and between samples makes comparisons difficult.  Further investigation of the impact of hormonal treatments on sperm motion characteristics within mucus would be of interest as would the combined impact on sperm transport once total volume of mucus produced/hormonal treatment was taken into account. Research supported by AWI, NSWSMBA Trust and Bioniche Animal Health A/Asia.