For many women with gynecologic malignancies, surgical intervention is only the beginning of treatment.Many patients require additional therapy. These patients need to be monitored for response to treatment, progression, or recurrence of disease. Monitoring a patient receiving chemotherapy or radiation may be difficult, as the currently available modalities do not have sufficient sensitivity or specificity to accurately predict persistent small-volume disease. How a patient is followed is often at the discretion of the treating physician and usually includes a combination of physical examination, serum tumor markers, imaging studies, and rarely, surgical reexploration. This chapter will discuss the role of tumor markers, imaging studies, and surgery in monitoring patients receiving chemotherapy for gynecologic cancers. Lacking prospective randomized trials, the recommendations put forth formonitoring these patients are largely based on expert opinion, nonrandomized studies, and clinical guidelines (1-3).