The objective of this study was to investigate the effect of hot waste oil vapor on some of the physical and bending properties of commercially manufactured thin medium density fiberboard (tMDF) panels. The samples were treated with waste oil vapor at a temperature of 220 degrees C for 10 and 20 min time durations. Based on the findings in this work, the water absorption and thickness swelling of the samples were improved by the treated panels with hot vapor oil and heat. It appears that the samples had some discoloration as a result of treatment processes. It was also observed that modulus of rupture (MOR) and modulus of elasticity (MOE) of the samples were adversely influenced. However, it seems that the thermal conductivity of the samples enhanced by such treatments. Panel products treated with these processes could have some promising potential in various applications including outdoor use. (C) 2009 Elsevier Ltd. All rights reserved.