Damask rose (Rosa damascena Mill.) is the most important species in the production of rose water, perfumes and essential oils (EOs), perfumery and pharmaceutical industry applications. In order to exploit the most of this precious Iranian flower, research was conducted on two damask rose genotypes (Fars 1 and Fars 2) in six development stages in terms of EOs content and composition analysis. Results showed that all development stages of damask rose genotypes had significant differences in the EOs content. The highest EOs content was obtained from "Fars 2" genotype. It was found that the oil obtained from the dried petals of Fars 2 genotype contained a higher percentage of citronellol (C), geraniol (G) and phenylethyl alcohol (PEA) as well as a suitable ratio of C/G with the value of 2.464 as compared with Fars 1 genotype (5.546). In the last stages of flower bud development in both genotypes, the sum of the main hydrocarbons increased while citronellol content decreased, therefore essential oil quality dramatically declined. EO quantity was lower in the middle stages of flower bud development (stages 3 and 4) as compared to the final stages (stage 5 and 6), but its quality was superior in the former stages. Generally, it seems that "Fars 2" damask rose, as a promising genotype, can be used for EO production.