Problem To identify plasma immuno‐regulatory molecules up or down regulated between the follicular phase and ovulation of the human menstrual cycle.Method of study RayBio® cytokine arrays were used to screen 174 immuno‐regulatory molecules in plasma collected during the follicular phase at menstrual cycle day 5 and at ovulation from five healthy, non‐smoking, fertile women of reproductive age not using hormonal contraception.Results A total of 23 differentially expressed molecules were found: 10 molecules were differentially up‐regulated and 13 down‐regulated at ovulation compared with that at the follicular phase (α = 0.05, false discovery rate of 0.45).Conclusion Circulating immuno‐regulatory molecules fluctuate over the menstrual cycle in healthy women. The combination of differentially expressed molecules suggests roles in cyclical regulation of angiogenesis and immune cell trafficking.