The present investigation was aimed to investigate the phytochemical profile of invasive weed species ‘Billy goat weed’ (Ageratum conyzoides L.) leaves using GC-MS techniques. Results of preliminary analysis of phytochemical screening showed that the presence of alkaloids, flavonoids, terpenoids, glycosides, steroids, tannins, volatile oils and,saponin in methanolic leaf extracts. In pet.ether, alkaloids, flavonoids and volatile oils were noticed. But in chloroform extract, alkaloids alone was found. The quinone was not found in all the five solvents i.e.pet. ether, methanolic, chloroform, ethanolic and aqueous extracts. The GC-MS study revealed the presence of thirty four compounds in the leaves of A. conyzoides. Among the identified compounds, the principal compounds are Glycerin (33.23%), Benzofuran, 2,3-dihydro (12.06%), n-Hexadecanoic acid (10.62%),2H-1-Benzopyran-2-one (8.35%) and 9,12,15-Octadecatrienoic acid, (Z,Z,Z) (7.611%).