Melanosis ilei is an extremely rare condition in which black pigment, consisted of aluminum, magnesium, or silicon, accumulate in the terminal ileal mucosa. Medical treatment with charcoal enhances the neutralization of the toxic material and elimination of many drugs. In addition, it has been used as a traditional remedy in some oriental countries to relieve chronic diarrhea, abdominal pain, or acute enterocolitis, which is made up carbon, oxygen, aluminum, magnesium, silicon, calcium, and palladium. Two patients taking the charcoal for a long time underwent a colonoscopy to evaluate chronic diarrhea or abdominal pain. The colonoscopy revealed a normal colonic mucosa and multiple geographic black-pigmented mucosal changes at the terminal ileum. Therefore, it was assumed that melanosis ilei can develop in patients with long-standing charcoal ingestion. To the best of our knowledge, this is the first case of melanosis ilei associated with the ingestion of charcoal.