Inclusion Criteria:

• Patients 18 years of age or greater
• Histologically documented diagnosis of ovarian cancer or primary peritoneal cancer. Histological subtypes include: mucinous tumor, serous tumor, endometrioid tumor, and other histologies including clear cell and undifferentiated epithelial tumors.
• At least one measurable site of disease (as defined by Southwestern Oncology Group Solid Tumor Response Criteria) or other response assessment criteria, as appropriate.
• Patients must have relapsed after receiving at least one prior platinum-based chemotherapy.
• Performance status of 0, 1, 2, (ECOG)
• Adequate end organ function: Total bilirubin < 1.5 x ULN, SGOT and SGPT < 2.5 UNL, creatinine < 1.5 x UNL, ANC > 1.5 x 109/L, platelets > 100 x 109/L.
• Patients will most likely have had their ovaries removed at the time off initial surgery. If any subjects are of childbearing potential at the time of entry, they must have negative pregnancy test within 7 days before initiation of study drug dosing. Postmenopausal women must be amenorrheic for at least 12 months to be considered of non-childbearing potential. Subjects of reproductive potential must agree to employ and effective barrier method of birth control throughout the study and for up to 3 months following discontinuation of the study drug.
• Written, voluntary informed consent.
• Patients must be eligible for care at a military medical treatment facility.

Exclusion Criteria:

• Patient has received prior treatment with Gemzar.
• Patient has received any other investigational agents within 28 days of the first day of study drug dosing.
• Patient is < 5 years free of another primary malignancy except: if the other primary malignancy is neither currently clinically significant nor requiring active intervention, or if other primary malignancy is a basal cell skin cancer or a cervical carcinoma in situ. Existence of any other malignant disease is not allowed.
• Patient with Grade III/IV cardiac problems as defined but the New York Heart Association Criteria.
• Patients who are pregnant or breast-feeding.
• Patient has a severe and/or uncontrolled medical disease (i,e. uncontrolled diabetes, uncontrolled chronic renal disease, or active uncontrolled infection).
• Patient has a known untreated or progressive brain metastasis.
• Patient has known chronic liver diseases (i.e. chronic active hepatitis, and cirrhosis.
• Patient has a known diagnosis of human immunodeficiency virus (HIV infection ).
• Patient received chemotherapy within 4 weeks (6 weeks for nitrosourea or mitomycin-C) prior to study entry, unless the disease is rapidly progressing..
• Patient previously received radiotherapy to greater than or equal to 25% of the bone marrow.
• Patient had a major surgery within 2 weeks prior to study entry.
• Patient with any significant history of non-compliance to medical regimens or with inability to grant reliable informed consent.