Follicular lymphoma (FL) is one of the most common non-Hodgkin's lymphomas in the United States, but it is relatively rare in Asia. FL typically arises in lymph nodes together with spleen, liver, and bone marrow involvement. So, primary extra-nodal FL without peripheral nodal involvement is rare. Histologically, it shows nodular aggregates of lymphoma cells and positivity for CD 10, CD 20 and bcl-2. Not only the stage, but also the grade is associated with the survival rate. Grade 3 FL presents a worse prognosis than does grade 1 and 2 FL and this should be treated with an anthracycline based CHOP regimen. We report here on a case of primary follicular lymphoma arising in the rectum; this was observed in a 58-year-old woman who complained of anorexia, dyspepsia and diarrhea. (Korean J Gastrointest Endosc 2006; 33:285288)