Lymphocytic colitis is a subtype of microscopic colitis characterized by normal colonoscopy findings and microscopic evidence of lymphocytic infiltration of colonic epithelial cells. The concomitant diagnosis of lymphocytic colitis and ulcerative colitis has been rarely reported. We present a 68-year-old man with a 40-year history of ulcerative colitis who was referred to our hospital for 3-4 weeks of non-bloody diarrhea with subsequent colonoscopy and biopsies confirming lymphocytic colitis.