The essential oil of \Rosa damascena Mill cultivated in central Iran (Kashan region) from the petals and whole flower (petals and retals), were extracted using a Clevenger apparatus in aqueous and acidic (10% v/v)solutions. Depending on the conditions of the steam distillation, eighteen major components of the essential oil extracts were identified by GC-MS in a 0.4-1% yield. The volatile components obtained from the retals were compared with the volatile oil from whole flowers (retals and petals) in aqueous and acidic solutions. The major differences were, first, some of the effective component in the retals, like \beta-citronellol, which is responsible for the higher quality of the rose oil obtained in a better yield, and, secondly, some of the toxic components, like 2-octanamine (0.47% in E sample), which can reduce the quality of the rose oil and which are completely removed in the acidic solution. According to the GC-MS results, \beta-citronellol (14.5-47.5%), nonadecane (10.5-40.5%), geraniol (5.5-18%) and henicosane (7-14%), were the major components of the oil.