The effect of arbuscular mycorrhizal (AM) fungi on root colonization, growth, essential oil content and composition and nutrient acquisition of basil (Ocimum basilicum) was investigated as complete randomized design with 4 treatments and 4 replications. Fungi inoculation treatments consisted: Gf (Glomus fasciculatum), Ge (Glomus etuonicatum), Gi (Glomus intraradices), and NM (non-mycorrhizal). The results showed mycorrhizal plants significantly had higher shoot and root dry weight, leaf area, plant height, numbers of lateral branches, as well as N, P, K, Ca, Fe, Cu and Mn concentration compared to non-inoculated plants. The effect of AM fungi inoculation on the root colonization, growth parameters and yield of basil are more pronounced with G. fasciculatum than other AM fungi. The G. fasciculatum inoculation significantly increased essential oil content and yield. Analysis of essential oil by GC and GC/MS showed that linalool formed the highest relative abundance of the main compounds in leaf essential oils of basil and methyl chavicol profile was considerably increased with AM fungi inoculation. Increased essential oil percent of AM fungi plants was correlated with root fungal colonization (r = 0.997**) and leaf P content (r = 0.994**). It is concluded that G. fasciculatum was more effective than other species, which may indicate effective symbiotic potential of this strain with basil roots. © 2010 Academic Journals.