This is a single-arm open-label Phase 2 study in patients with peritoneal carcinomatosis of ovarian origin that are not eligible for curative treatments. Patients will receive 5 weekly IV infusions of JX-594 until radiographically determined progressive disease. Patients will be allotted in a 1:1 ratio to undergo a laparoscopy and tumor biopsy 10 days after dose 1 or 10 days after Dose 5. Patients will be monitored on study until evidence of progression or death or for 12 months post treatment.