Some of the synthetic dyes and mordants are harmful to the environment. The aim of this research was to study the dyeing of cotton fabric using extracts from wild leek (Allium burdickii). The bark of mango tree was used as a mordant. The pre-mordanting method was used and four treatments were investigated with respect to exhaustion of the dye. These were: temperature, time, pH and concentration of mordant. Dye exhaustion for 27 experiments was investigated by comparing the relationship between the independent and dependent variables. The regression model obtained from the interactions was significant with an R2 value of 0.611. The effect of pH was insignificant while all the other three variables significantly influenced exhaustion of dye. The optimised conditions for temperature, time and concentration of mordant were: 600C, 90 minutes and 28.18% owf, respectively. The fabrics showed acceptable fastness properties ranging from 2/3-4/5 (fair to very good), 1.2-4 (slightly considerable to noticeable) and 4-5 (very good to excellent) for wash, perspiration and rubbing fastness, respectively.