The production of biodiesel from a naturally isolated strain of Chlarrydomonas was investigated. The microalgal strain was isolated from the rice paddy-field soil samples during a screening program. The identification was done using physiological and molecular approaches. After reaching the stationary phase of growth, the total content of the lipids was extracted. The extracted fatty acids were primarily esterified and then identified through TLC and GC/MS analysis. Several types of fatty acid methyl esters (FAMEs) were identified in the isolated microalga and the presence of at least nine FAMEs in Chlamydomonas sp. MCCS 026 was shown, The total fatty acid content of the isolated strain was 25%. The composition of fatty acids in the studied species of microalga was mainly docosanoic acid methyl ester, tetradecanoic acid methyl ester, hexadecanoic acid methyl ester and nonanoic acid methyl ester. (C) 2009 Elsevier Ltd. All rights reserved.