Changes in serum progesterone (P), oestrone (E1) and oestradiol (E2) concentrations were monitored in 34 female red deer (Cervus elaphus) shortly after the end of the breeding season and at mid-gestation. Pregnancy could be detected on the basis of serum P, but there were no significant differences between the pregnant and non-pregnant animals farmed animals in E1 and E2 concentrations. Twenty-five pregnant hinds captured in winter showed serum P levels similar to those found in farmed deer during the gestation period.