Second generation bioethanol production from dried biomass of a common weed Parthenium hysterophorous was investigated using separate hydrolysis and fermentation method. The biomass was found to contain 53.63% of holocellulose, 10.44% lignin, 0.87% extractives, 26.06% others and 9.00% ash. The effects of pretreatment of the biomass with each of the three acids (hydrochloric, sulfuric and phosphoric) and two alkalis (sodium hydroxide and potassium hydroxide) under two temperature regimen (cold hydrolysis at room temperature and hot hydrolysis at 121 degrees C), followed by detoxification of inhibitors and treatment with different concentrations of cellulase enzyme were studied. Three yeast strains viz., Torulaspora delbrueckii R3DFM2, Schizosaccharomyces pombe R3DOM3 and Saccharomyces cerevisiae R3DIM4 were used for fermentation. The maximum yield of total reducing sugars obtained was 615 mg/g of the biomass. Yields of ethanol obtained on the detoxified lignocellulosic broth under optimal conditions were 0.24, 0.27 and 0.27 g/g biomass. The present work lends support to the use of Parthenium biomass as a viable source for second generation bioethanol production from non-agricultural feed stock. (c) 2015 Elsevier Ltd. All rights reserved.