Crohn's disease (CD) patients may be at increased risk for the development of Hodgkin's lymphoma (HL) or non-Hodgkin's lymphoma (NHL), either through exposure to immunosuppressive medications or due to their underlying chronic inflammatory illness. There are limited data regarding the natural history of CD following treatment of lymphoma. We present a series of CD patients who were treated for lymphoma and describe the natural history of their CD following lymphoma treatment. Retrospective case series from three academic referral centers was used. All CD patients with a history of lymphoma were identified. Demographic data, CD medication exposure, and surgical procedures before and after lymphoma treatment were recorded. Nine CD patients with a history of lymphoma were identified. Eight individuals received chemotherapy, while one patient was observed without treatment. Eight patients remained free of lymphoma for a mean of 72.8 months (range 1-276 months). The ninth patient had recurrence of his HL 3 years after lymphoma diagnosis. Following lymphoma treatment, two patients had quiescent CD with no specific therapy. Three patients demonstrated significant clinical relapse of their CD and a fourth patient developed CD after treatment of her lymphoma, which ultimately required long-term immunomodulator therapy with 6-mercaptopurine or methotrexate in the first three patients, and azathioprine in the fourth. Four patients required CD surgery after lymphoma treatment. We report on the clinical course of CD in patients who develop lymphoma. Significant clinical relapse of CD following successful medical treatment of lymphoma occurred frequently in patients with a history of this neoplasm.