This is a prospective, observational community cohort study with the objective of investigating menstrual cramp occurrence related to ovulatory characteristics. Women reported cramp intensity on daily Menstrual Cycle Diary© records over one year. Ovulation and luteal phase lengths were assessed by validated Quantitative Basal Temperature© (QBT) analysis. Healthy, normal-weight, non-smoking community dwelling premenopausal women ages 21-41 years with two consecutive, normally ovulatory, normal-length menstrual cycles were enrolled. All 53 women, with 13.6 ± 2.8 cycles per woman, reported at least one cramp episode of median intensity 1.5 [0-4 scale; range 1.0-3.5], and 2.2 days' [range 1.0-10.2] duration. Within the 49 women who experienced all ovulatory cycle types (normal, short luteal length [SLL