INTRODUCTION: Resting heart rate variability (HRV), a marker of parasympathetic activity, is a predictor of health and longevity. Better erectile function is associated with greater resting HRV (assessed by high frequency power [HF]), and in both sexes, penile-vaginal intercourse (PVI) is the only sexual behavior consistently associated with indices of better physical and mental health, including greater resting HRV (assessed by standard deviation [SD] of heart rate [HR]). AIMS: To examine the hypotheses that greater frequency of orgasms attained through PVI (for women, without additional simultaneous clitoral stimulation; vaginal orgasm) are associated with greater resting HRV. A differential hypothesis is that HRV measures will be unrelated to orgasmic frequency from noncoital sexual activities. METHODS: Coitally experienced men and women (N = 143) had their heart rate measured for 5 minutes and reported the frequency of various sexual behaviors and corresponding orgasms in a recent representative month. MAIN OUTCOME MEASURES: Partial correlations and analyses of covariance controlling for social desirability responding were used to examine the associations of sexual activities with time and frequency domains of HRV. RESULTS: For men, greater resting SD of HR was associated with greater PVI orgasm frequency. For women, greater resting SD of HR was associated with any vaginal orgasm. These findings remained after controlling for cohabitation. Sexual activities were unrelated to HF. Lifetime number of PVI partners was unrelated to SD of HR and HF. CONCLUSIONS: Findings are discussed in the context of orgasms through PVI enhancing HRV, and greater parasympathetic tone favoring the capacity to engage in PVI, and in the case of women, to reach vaginal orgasm. The possibility of healthier people having greater resting HRV and more frequent orgasms through specifically PVI is also considered.