Cotton fabric with a deodorizing function is prepared by mordant dyeing with direct dyes containing copper ions and copper(II) nitrate. The effects of pre- and after-mordantings and after-treatment with copper(II) nitrate are examined for C.I. Direct Violet 47 and C.I. Direct Black 112. The copper ion uptake of cotton dyed with pre- and after-mordantings is about I/IO the value for wool samples. The elimination of ethyl mercaptan from air by the mordant dyed fabrics is measured in a Teddler bag. Untreated cotton fabric shows no deodorizing ability, but each of the pre-mordanted, dyed, after-mordanted, and after-treated fabrics shows a considerable deodorizing ability. The effects of after-mordanting and after-treatment are particularly notable, implying that they are caused by dye-copper ion complexes.