The aim of this work was to study the effect of four different types of thermal pretreatment techniques i.e., hot air oven, microwave, autoclave and hot water bath on the hydrolysis, compositional analysis and characterization of water hyacinth. To determine the most efficient thermal pretreatment technique exhibiting enhanced solubilisation. Highest solubilisation was achieved by hot air oven (55.5%), followed by microwave, hot water bath and autoclave. Bio-chemical methane potential (BMP) test of hot air oven pretreated and untreated water hyacinth was conducted. Cumulative methane production of 3039 +/- 32 mL CH4/g VS was achieved by hot air oven pretreated water hyacinth at 90 degrees C for 1 h which was way higher than the cumulative methane production of untreated water hyacinth 2396 +/- 19 mL CH4/g VS on the 35th day. Compositional analysis and characterization of water hyacinth were also investigated to study the changes in the pretreated samples. (C) 2016 Elsevier Ltd. All rights reserved.