Previous research has identified the cholinergic system as a critical component for both behavioral and gonadotropic processes of the female rat. In the present study, changes in 3H-quinuclidinyl benzilate (3H-QNB) binding to CNS muscarinic receptors were compared to changes in ovulatory and behavioral mechanisms in the neonatally androgenized female rat. The incidence of lordosis behavior and regular estrous cycles decreased as a function of increasing dosage of neonatal testosterone. Androgenization of the animals significantly reduced binding of 3H-QNB in the ventromedial hypothalamus (VMH). Furthermore, administration of estradiol benzoate prior to sacrifice significantly decreased specific 3H-QNB binding in VMH. Binding was not altered significantly in the medial preoptic area, the midbrain central gray, or the corpus striatum as a function of neonatal androgen treatment or estrogen administration. Evidence from this study which conflicts with those published previously on the influence of estrogen on cholinergic receptor binding is critically evaluated on the basis of timing and dosage variables. Furthermore, the proposal that changes in cholinergic receptor dynamics influence the normal age-related decline in female reproductive capability is discussed