Many Trichoderma isolates are known to secrete several secondary metabolites with different biological activities towards plants and other microbes. The production of such compounds varies according to the strain. In the present study, volatile secondary metabolites from the culture filtrate of Trichoderma asperellum strain were characterized using Gas chromatography-Mass spectrometry (GC-MS). Results of GC-MS detected 43 secondary metabolites in the T. asperellum strain including many important volatile secondary metabolites such as 1,2-Benzenedicarboxylic acid, 2-butoxy-2-oxoethyl butyl ester (peak area-3.59%), 1,2-Benzenedicarboxylic acid dibutyl ester (peak area-2.02 %), 2H-Pyran-2-one (peak area-66.63 %), palmitic acid (peak area-2.86 %), several phenolic isomers, methyl cyclohexane etc., all reportedly having effective pesticidal activity. The results indicated that these secondary metabolites could be useful for biological control applications of T. asperellum strain against diverse plant pathogens