Thefatty acid composition of infective juveniles (IJs) related to five isolates ofHeterorhabditis indica (EGAZ1, EGAZ2, EGAZ3, EGAZ4, and EGAZ5) and threeisolates of Steinernema carpocapsae (EGAZ9, EGAZ10 and SA)collected from five Egyptian Governorates was assessed. Also, fatty acidcomposition of IJs from two commercially relevance strains of H.bacteriophora (HP88)and S. carpocapsae (All), was examinedfor comparison. Newly emerged IJs of all isolates had fatty acid number andpattern similar to that of the corresponding commercial species. Of the tenfatty acids identified, oleic, was the main fatty acid in all species andisolates. Unsaturated fatty acids were dominant and total amount of saturatedfatty acids of H. indica isolates was significantly higher than that of S.carpocapsae isolates. Palmitic was the second most abundant fatty acidin IJs of H. indica isolates, while linoleic was the second mostabundant fatty acid in IJs of S. carpocapsae isolates. Ofthe tested Egyptian isolates, IJs of EGAZ3 and EGAZ5 of H. indica hadthe highest amounts of fatty acids and their contents of saturated fattyacids/gram body weight are comparable to that of the commercial strain. It is suggested that isolates EGAZ3 and EGAZ5of H. indica are the candidates for developing practical Egyptianbio-control product based on nematode formulation.