In the recent years, water resources for successful plant production are decreased and many parts of the world are exposed to drought stress. Improving plant tolerance and maintaining productivity under environmental stresses such as drought is a major issue in agriculture. In addition to, the inherent capacity of the plant stress tolerance, inoculation with mycorrhizal fungi may increase plant tolerance to stress and as a result preserve plant growth and yield. Rose geranium ( Pelargonium graveolens (L.) Heritier) is an ornamental-medicinal plant from Geraniaceae which is cultivated mostly for its valuable essential oil. The present experiment was conducted as a factorial experiment based on CRD to study rose geranium response to inoculation with different mycorrhizal species ( G. mosseae, G. intraradices and the combination of both species) and three irrigation levels (50, 75 and 100% FC) with 3 replications. The results showed that the severe water deficit caused a sharp reduction in root colonization by mycorrhizal inoculation. The highest total glomalin was observed at 75% FC together with G. mosseae and the combination of both mycorrhizal species. Also, the results showed that fresh weight and other growth factors were increased by the combination of both mycorrhizal species and G. mosseae , in non-stress condition and 75% FC, respectively, as compared to non-mycorrhizal inoculation. Application of mycorrhizal fungi had no significant effect on reproductive traits such as flowering time, flowering period and number of inflorescence but these triats have affected by irrigation regimes, so that flowering time decreased by about 19 and 80% at 75 and 50% FC compared to the control, respectively. Inoculation with G. mosseae significantly increased total chlorophyll at 100 and 75% FC. The results showed that by reducing the irrigation water, proline content was increased at 75 and 50% FC and mycorrhizal inoculation decreased proline at severe water deficit. According to our results, inoculation with G. mosseae caused a significant increase in the concentration of nitrogen at 100 and 75% FC. Mycorrhizal inoculation sharply increased P concentration, so that inoculation with G. mosseae and combination of both of mycorrhizal species showed the highest P absorption. Also, leaf Zn and Fe concentrations were decreased at 50% FC though, the latter attributes were increased when the plants were subjected to a combination of both of mycorrhizal species. The highest essential oil was observed in plants growth at 75% FC and inoculated by G. intraradices (34.1% increased relative to control). According to the results of this study, it can be concluded that the beneficial effects of inoculation with mycorrhizal fungi of geranium plants resulted in improved water relations, nutrient absorption, yield and increased essential oil content at stress and non-stress conditions. According to the results of this study, inoculation with mycorrhizal can be particulary beneficial to rose geranium when grown at water limited conditions. Keywords : Mycorrhizal fungi, Rose geranium, Irrigation deficit, Nutrient elements, Medicinal plants, Essential oil