The present study utilizes natural dyestuffs which would not contribute to environmental pollution and undertaken to explore promising approach to reduce costs of dye process. However, the natural dyes of henna and onion skin were used to dye different fabric materials, i.e 100 % cotton, 100 % polyester and 35 % cotton / 65 % polyester blend. The low temperature 30 °C and the high temperature 100 °C under closed dyeing system were applied in this study. The results indicated that, using the natural dyes (henna and onion skin) with the previously mentioned fabrics under the low temperature (30° C) resulted in an increase in fabric strength of the 100 % cotton fabric and the 35 % cotton / 65 % polyester blend, while no change in fabric strength of the 100 % polyester material. Thus it appeared that using these natural dyes would not cause any deterioration in fabric strength. On the other hand, the fabric elongation was not affected by the dyeing process. While the results showed that the shrinkage values of dyed fabrics with henna were generally lower than the corresponding values of dyed fabrics with onion skin. However , all fabric materials under this study when dyed with henna and onion skin, revealed higher fastness to light and wash, lower fastness for alkali and acid perspiration. Finally, it was observed that using high temperature and closed dyeing system was not suitable for dyeing these kinds of fabrics with henna and onion skin dyes.