This study analyses the social, physiological and motivational determinants of sexual activity for 644 married women in rural areas of Osun State, Nigeria. The data come from the Fertility Awareness and Pregnancy Avoidance study conducted in 1993–94. Sexual activity is measured by three continuous variables: weekly frequency of (1) total sexual activity, (2) coital-only sex and (3) both coital/non-coital sex. Analyses of variance were performed to test the difference in group means between the predictor variables and measures of sexual activity. Ordinary least squares regression analyses were then performed for the three dependent variables. Two models are used: the first contains only those variables associated with an individual’s demographic, social and economic status, and the second adds predictor variables associated with motivational and physiological factors. Results show that while many socioeconomic variables by themselves are significantly associated with sexual activity measures, the addition of physiological and motivational variables weakens their effects and lessens their original statistical significance. Additionally, the socioeconomic and demographic factors associated with frequency of sexual activity are not necessarily the same ones significantly associated with coital-only or combined coital/non-coital sex. While other studies have tended to focus either on socioeconomic or physiological factors, the joint examination of both types of influences seems to indicate that the latter have more proximate effects on the frequency of both coital and non-coital sexual activity of married women in this population. Contraceptive protection is shown to be highly positively associated with all three of the sexual activity measures, empirically confirming the important relationship between contraception and both coital and non-coital forms of sexual activity.