Preeclampsia is uncommon prior to 24 weeks gestation and has been associated with partial and complete hydatidiform moles. We present an unusual case in which a patient was diagnosed with preeclampsia at 17 weeks gestation. Ultrasound findings were consistent with a partial hydatidiform mole. Within 24 hours of the onset of symptoms, the patient developed severe hemolysis, elevated liver enzymes, and low platelet count syndrome, with a platelet count of 20 x 10 (9) cells/L. Termination of pregnancy was performed with rapid resolution of signs, symptoms, and laboratory abnormalities. Triploid 69,XXY was confirmed at karyotype analysis. This case demonstrates the acuteness in which life-threatening maternal conditions can arise with this uncommon complication of pregnancy, and the importance of correct identification of the characteristic ultrasonographic findings associated with a partial hydatidiform mole.