This article uses a prospectively, annually collected sexuality questionnaire from an 8-year study of 340 mid-aged Melbourne women. We modeled the interactions of sexuality domains, the effect of prior level of sexual functioning, and the effects of change in partner-related factors. We found that we were unable to separate items denoting sexual interest from those denoting responsiveness. Using the statistical technique of auto-correlation, we determined that the most important predictor of female sexual functioning is prior level of sexual functioning. Partner-related factors (change in partner status and feelings for partner) also had significant effects.