This investigation deals with improvement of dyeing properties of Egyptian cotton fabrics of varieties namely Giza 83 and Giza 89, with natural dye from a yellow pigment fraction isolated from the rhizomes curcuma of longa by enzymatic pretreatment. The dyeing technique was performed by simultaneous mordanting technique (sample-dye-mordant) without enzyme, and after the enzymatic treatment. Different mordants namely iron (II) sulphate; alum, potassium dichromate, and copper sulphate were applied in this technique. The mechanism of dyeing is discussed. Dyeing performance in terms of fastness properties and color parameters are studied. The results obtained revealed that the simultaneous mordanting technique(sample-dye-mordant) after the enzymatic treatment resulted in an increase in dye uptake in all cases compared with the untreated or the simultaneous mordanting technique without enzymatic pretreatment samples, and did not affect fastness properties. The color strength (K/S) values, fastness properties and also the response to dyeing were higher for Giza 89 than Giza 83 due to its higher hydroxyl groups on the fabric surface causing increase in the charged sites by using the lone pair of electrons on the functional groups between the molecular structures of the reactants.