Background: We evaluated the efficacy of intraperitoneal (IP) carboplatin in combination with dose-dense paclitaxel (ddTCip) for suboptimal residual ovarian cancer. Methods: This was a phase 2 study to evaluate ddTCip. Patients with stage II–IV ovarian carcinoma, who underwent primary cytoreductive surgery and had radiologically evaluable disease after surgery, were eligible to participate in this study. IP carboplatin (AUC = 6) was administered on day 1, and intravenous paclitaxel (80 mg/m2) was administered on days 1, 8 and 15. The primary endpoint was response rate. Secondary endpoints included progression-free survival (PFS), overall survival (OS) and safety. Interval- debulking surgery followed by the same regimen was allowed when indicated. Results: A total of 117 patients were considered eligible for this study prior to surgery and temporarily registered. Of the 117 patients, 76 patients met the inclusion criteria and were enrolled in this study. Fifty-nine (83.1%) patients had objective clinical responses. Median PFS and OS were 18.3 and 55.5 months, respectively. Sixty-four (84.2%) patients had grade 3/4 neutropenia, 43 (56.5%) patients had anaemia and 17 (22.4%) patients had thrombocytopenia. Port-related adverse events occurred in nine (11.8%) patients. Conclusions: Front-line chemotherapy with ddTCip therapy appears safe and effective, even for patients with suboptimal residual ovarian cancer. Trial registration: UMIN Clinical Trials Registry (ID: UMIN000001713) on February 16th, 2009.