Reports of cytomegalovirus (CMV) colitis mainly concern patients with immunocompromisation resulting from, among others, HIV infection, allogeneic bone marrow transplantation and solid organ transplantation. CMV colitis rarely occurs during standard chemotherapy for non-Hodgkin's lymphoma (NHL). An unusual case of CMV enterocolitis in a 62-year-old patient is reported. After a first course of salvage chemotherapy for NHL, diffuse erosions and sloughing mucosa were seen throughout the large bowel. The final diagnosis was based on histological findings. Although ganciclovir and foscarnet are effective for CMV viremia, their use in the treatment of severe diarrhea in our patient did not result in improvement for one week, whereas concomitant use of octreotide led to rapid improvement. Octreotide may therefore be an effective agent for severe colitis.