Endometritis is diagnosed cytologically, as endometrial inflammation, or clinically as purulent or mucopurulent vaginal discharge. Cytological endometritis (CYTO) is based on an increased proportion of polymorphonuclear cells in endometrial cytology. Purulent vaginal discharge (PVD) has only moderate diagnostic agreement with CYTO. The prevalence of CYTO and PVD have been reported to be as high as 53 and 40%, respectively. Reported risk factors for PVD include dystocia, retained placenta (RP), and metritis. Little information is available on the risk factors for CYTO. Cytological endometritis and PVD were shown independently to have detrimental effects on subsequent reproductive performance. Conflicting results have been reported regarding the effect of prostaglandin F2alpha (PGF) on uterine health and reproduction. The hypotheses were that CYTO and PVD would have different risk factors because they represent different reproductive diseases, and that treatment with PGF would mitigate the impact of CYTO and PVD. The objectives of this study were to investigate risk factors and impacts of CYTO and PVD in postpartum dairy cows, and to determine the efficacy of PGF for treating CYTO and PVD and for improving reproductive performance.