Summaryobjective  Oestrogen and progesterone are known to influence the release of human prolactin. The present study was undertaken in order to investigate the possible influence of polymorphisms of the genes encoding the oestrogen receptor (ER)α, ERβ and the progesterone receptor (PGR), on prolactin levels in premenopausal women.design and measurements  Serum levels of prolactin were measured in the follicular phase of the menstrual cycle. Subjects were genotyped with respect to a TA repeat polymorphism of the ERα gene, a CA repeat polymorphism of the ERβ gene, and two polymorphisms of the PGR gene: one insertion polymorphism (PROGINS) and one single nucleotide polymorphism (G331A).subjects  A population‐based cohort of 270 42‐year‐old women.results  The CA repeat polymorphism of the ERβ gene and the G331A polymorphism of the PGR gene appeared to be associated with prolactin levels. In contrast, we found no evidence for an influence of the PROGINS polymorphism of the PGR gene or the TA repeat polymorphism of the ERα gene on the levels of this hormone.conclusions  These data suggest that genetic variants of both the ERβ and the PGR may influence prolactin release.