This study aimed to investigate?the treatment effect?of dimethyl silicone oil on archaeological dried leather. Leather samples, without treatment and treated in a vacuum, were submitted to an accelerated aging at 100°C for 72 hours. In order to evaluate the efficacy of treatment, leather characteristics were examined before and after treatment with dimethyl silicone oil and after accelerated aging. Colorimetry, ATR-FTIR spectroscopy, shrinkage temperature measurement and differential scanning calorimetry were used to examine the leather characteristics and the effectiveness and stability of treatment. The results revealed that the dimethyl silicone oil has a suitable performance in the treatment of dry leather. The results also showed that the use of dimethyl silicone oil significantly reduces the changes in leather during accelerated aging. In other words, dimethyl silicone oil treatment improves the leather stability against deterioration.