Background and rationale: Non-curative surgical cytoreduction of advanced tumors is associated with increased proliferation of the remaining tumor cells. Thus, appropriate preoperative chemotherapy should prevent both cell proliferation and the increase of resistant cells. The aim of the present study was to evaluate the efficacy and toxicity of primary chemotherapy (P-CT) in previously untreated patients with stage IV ovarian cancer (OC). Patients and methods: Thirty-four patients with stage IV OC were treated from January 1993 to April 2000 with P-CT. Eligibility criteria included: histologically or cytologically confirmed, unresectable stage IV OC and perfomance status ≤ 3. P-CT consisted of four courses of carboplatin, cyclophosphamide and epirubicin until October 1996, and paclitaxel, carboplatin thereafter. Surgery followed P-CT. After the operation patients received two further courses of chemotherapy that were tailored according to their individual response. Median (M) age was 61 years, range 32-73; median performance status was 2. A total number of 197 courses of CT were administered, median 5.7 per patient. Results: Complete or partial response (CR, PR) was observed in 28 patients (response rate 82%, 95% CI: 65.4% to 93.2%), disease stability and progression (SD, PD) was observed in three and three patients, respectively. Median time to progression was 16.45 months (range 4.8-90.4+), median survival time was 28 months (range 4.5 - 90.4+); I-year survival rate was 94%. Toxicity according to WHO: nausea and vomiting grade (G) 2, 30% of patients; gastrointestinal G 2-3, 20% of patients; alopecia G 3, 88% of patients; hematological G 3-4, 73% of patients; neurologic G 2, 12% of patients. Nine pathological CRs were observed. Conclusion: Neoadjuvant treatment with CBDCA with either CTX and EPI or Taxol is feasible and shows activity in OC.