In this study, dyeing properties of cotton fabrics with red cabbage extract as a natural colorant and by mordanting materials like potassium aluminumsulphate and tannic acid were investigated. Pre-mordanting, simultaneous mordanting and post-mordanting methods were used for mordanting of cotton fabric and natural dyeing process was carried out by exhaustion method. Moreover, since it is known that red cabbage presents different colors in different pH values due to its indicator property, the trials were renewed for three pH conditions as acidic, basic and neutral. After dyeing processes, color measurement, washing and rubbing fastness tests were applied to the samples. As a result of the study, it was observed that red cabbage extract can be used to dye cotton fabrics and the most permanent colors can be obtained in neutral pH conditions. When mordanting methods and mordanting materials were compared to each other, it was determined that various color shades were provided according to the mordanting materials and methods. In terms of general, it was concluded that uniform dyeings with high color yield can be obtained by tannic acid mordant and pre-mordanting method and high mordant concentration should be used to get dark color shades. In addition, washing and rubbing fastness values were determined to be in acceptable limits for natural dyeing.