An epidemiological study of risk factors for postpartal ovarian disturbances was carried out on 334 high-yielding dairy cows in 6 well-managed Belgian herds. Ovarian activity was closely monitored using progesterone profiles, based on twice weekly RIA-analysis for progesterone in milk fat, starting at 10 d after calving and continuing until the confirmation of a new pregnancy. Attention was focused on abnormal cyclicity during the preservice, postpartum period; cows were divided into 6 different categories. Three of these categories (normal profile, delayed cyclicity, and prolonged luteal phase) were of major importance and were analyzed using a multiple variable logistic regression model. Season of calving (stable vs pasture, odds ratio (OR) = 5.7), an extended length of the previous dry period (>77 vs ≤63 d, OR = 2.9), problem calvings (OR = 3.6), abnormal vaginal discharge (OR=4.5), health problems during the first month of lactation (clinical disease, OR = 5.4; ketosis, OR = 11.3), and clinical parameters illustrating the appearance of a severe negative energy balance significantly increased the risk for delayed cyclicity before service. Parity (≥4 vs 1, OR = 2.5), problem calvings (OR = 2.9), occurrence of puerperal disturbances (OR ranged from 3.5 to 11.0), health problems during the first month of lactation (OR = 3.1), and an early resumption of ovarian cyclicity after calving (<19 d vs >32 d, OR = 2.8) increased the risk for prolonged luteal cycles before service.