Objective. To determine the radiographic characteristics of ovarian granulosa cell tumors (GCTs) and to evaluate the use of CA125 levels >35 in combination with imaging as an algorithm for preoperative diagnosis. Methods. A retrospective analysis of women from two academic medical centers who were diagnosed with ovarian GCT between January 1998 and August 2012 was conducted. Clinical data included tumor appearance on pre-operative imaging and CA125 levels. Ovarian cysts were defined as complex if imaging exhibited multicystic areas, hemorrhagic, solid, or cystic and solid components. A CA125 level >35 was abnormal. Results. One hundred and fifteen women were diagnosed with GCTs, of whom 63 underwent pre-operative imaging. Median age at surgery was 46 years (12-87). Forty women had preoperative ultrasounds, 43 had CT scans and 20 underwent both modalities. GCTs were almost exclusively classified as complex cysts in 62 (98%) cases. Themost commonmorphologywas solid and cystic (n = 44 (70%)). Forty-four (70%) patients had tumors >10 cm. Forty-two patients had a pre-operative CA125 performed. Eighteen (43%) patients had complex masses and CA125 >35. Twenty-three (55%) had CA125 <35 with a complex mass, and one (2%) had a unilocular cyst with a CA125 >35. Conclusions. In this study, there was a near equal distribution of patients with complex masses and CA125 levels > or <35. If established strategies to predict malignancy are applied to GCTs, we will frequently fail to make the diagnosis pre-operatively. Additional research is necessary to generate an appropriate algorithm to guide pre-operative referral to a gynecologic oncologist. © 2013 Elsevier Inc. All rights reserved.