Symbiotic relationship between some members of Poacea family and a group of fungi called endophytes has been established. These symbionts belong to Clavicipitacae family previously known as simple parasites of plants. These fungi grow intercellularly in the leaf sheets of host plants then enter the seed through the overy and stay in aleuron layer until seed germination. Presence of these fungi in plants leads to resistance against drought, improves photosynthesis and resistance to pests and diseases. Several alkaloids such as lolin, peramin, lulitrom, and ergovalin produced by the endophytes are responsible for the plant resistance against biotic and a biotic stresses. Thus, knowledge on the genes involved in the alkaloids biosynthesis is useful in the field of plant breeding. Keeping these beneficial fungi in host crops may lead to persistant production during years and in different environments and will provide scientists with new sources of germplasm for selecting resistant plants . This study was designed to detect genes of endophytic fungi associated with insecticidal alkaloids in several forage grasses including Melica persica, Festuca arundinacea, Lolium prenne and Bromus tomentellus. After isolation morphological characteristics were investigated on PDA medium. Then genomic DNA was extracted from isolates to confirm the genus identity using specific primers IS1 / IS3, ITS1/ITS4 and 11-1/11-2. In most of the isolates the 444 bp band was amplified with the IS1/IS3 primer pair. Also in a number of isolates the 1000 bp band was amplified by 11-1/11-2 primers. No amplification was possible with ITS1/ITS4 primers. Based on morphological characteristics and specific primers most endophytes isolated from Festuca arundinaceae, Lolium prennea, Melica persica and Bromus tomentellus were identified as Neotyphodium. To detect genes involved in synthesis of alkaloids lolin, peramin, ergovalin and lolitrum PCR reactions were set using specific primers. Amplification of bands with the expected size was taken as evidence for the presence of the genes in the isolates. All the expected bands were amplified in an isolate (LpMd) that belonged to Lolium prennea. This may indicate the presence of all four genes in this isolate. On the other hand, no amplification was observed for isolates Lp and MpDe belonging to the hosts Lolium prennea and Melica persica respectively. Our result showed that designing specific primers it may be possible to detect genes responsible for insecticidal alkaloids in Neotyphodium isolated from different grass hosts.