Conversion of cotton-based waste textiles to ethanol by enzymatic degradation and fermentation was investigated. The materials used were cotton linter and a waste material from blue jeans textiles. The cellulose contents of these materials were 98% ± 1% and 93% ± 1%, respectively. The cotton and jeans with no pretreatment were enzymatically hydrolyzed to glucose by cellulase and bglucosidase for 2 days, and resulted into 24.1% and 23.6% digestion, respectively. Hydrolysis of pure cellulose (Avicel) at identical conditions was more successful, where 38.7% of the cellulose was converted to glucose. Pretreatment of the textile materials by concentrated phosphoric acid improved their digestibility. The cellulose parts of the materials were completely dissolved in the acid, and then precipitated using acetone, where 70–80% of the initial materials were recovered after the precipitation. It resulted in improved glucose yield in the enzymatic hydrolyses, where 63.4% and 60.7% of the cotton linter and the jeans were digested, respectively. However, better results obtained by the alkali pretreatment of the cotton and jeans (data not shown). Cotton linter was then chosen as a sample of cotton textiles to study the effect of temperature and NaOH concentration on the enzymatic digestibility of the material. The material was treated at 0 C, 23 C and 100 C with 0–20% NaOH for 3 h. The treated materials remained solid in the solution, but swelled, where more than 95% of the initial materials were recovered after the washing. The most important results of digestion of pretreated cottons are summarized in Table 1. The results show great effects of treatment temperature and NaOH concentration on the rate of enzymatic hydrolysis. The best results were obtained at cold temperature (0 °C), where more than 85% of the theoretical glucose yield could be obtained within 24 h enzymatic hydrolysis of treated cotton by 12% NaOH solution (Table 1). Furthermore, increasing the concentration of NaOH enhanced the digestibility. However, for pretreatment at 0 °C, the concentration of 12% was the critical dosage and no significant improvement in digestibility was obtained when using higher concentration of NaOH. Temperature had a negative impact on the rate of enzymatic hydrolysis. The initial enzymatic hydrolysis rate during the first day was practically the same for all three temperatures until 8% NaOH concentration used (Table 1). However, at higher concentration of sodium hydroxide used, lower temperature was more effective for increasing the hydrolysis rate. The best digestion results were obtained at 12% NaOH and 0 °C, where 99.1% of the cotton was digested to glucose within 4 days.