Introduction: We performed a systematic evaluation of tumor pattern and surgical outcome in 214 consecutive patients with primary ovarian cancer. Methods: Based on the surgical and histological reports we retrospectively analyzed tumor localizations, surgical and clinical outcome. Coxregression analysis was performed to identify independent predictors of complete tumor resection and mortality. Results: Median age was 57.7 years (range: 20-88). FIGO-stage-I was classified in 8.4% and IV in 16.4% of all patients. The peritoneum was the structure most affected (76%) followed by the colon (52%) and diaphragm (44%). Upper abdominal tumor involvement was associated with a significantly higher rate of lymph node metastasis and a significantly lower rate of complete surgical tumor resection, when compared to patients with tumor limited to the lower abdomen. Median overall survival was 56; 61 and 27 months for patients with tumor load in the upper, lower and whole abdomen respectively (P < 0.05). Conclusions: The intraoperative tumor dissemination pattern and the post-operative tumor residuals are decisive for the prognosis in primary ovarian cancer. There is an urgent need to use a systematic and standardized tumor documentation protocols to define the predictive and prognostic role of specific tumor pattern and to compare the surgical outcomes of different tumor centers.