Ulcerative colitis (UC) is defined as a chronic inflammatory condition causing continuous mucosal inflammation of the colon without granulomas on biopsy. It affects the rectum, and, to a variable extent, the colon in continuity and is characterized by a relapsing and remitting course. Oral 5-aminosalicylic acid (5-ASA) regimens are recommended as first-line induction therapy for mild to moderately active pediatric UC and for maintenance of remission regardless of other initial treatments. In large clinical trials in adults, mesalamine intolerance was found in 2-5 % of the patients. We present a case of an 8-year-old female patient with intolerance to mesalamine and proctitis resistant to conventional therapy who responded to rectal tacrolimus treatment. The patient started with a dose of 2 mg/day at night with an excellent response. She reported feeling better than any of the previously prescribed treatments and without feeling the discomfort of previously administered enemas. After four weeks of treatment, the dose was reduced to 2 mg/week with no relapses. Tacrolimus suppositories were very well tolerated, and no adverse effects have been reported. Although only very little data has been published, rectal tacrolimus seems to be safe and of efficacy in ulcerative proctitis resistant to standard therapy.