The liquefied petroleum gas (LPG) is generally considered to be eco-friendly viable fuel not only in domestic sector but also for transport sector. The inhibition of LPG-air premixed flames is a very important practical problem that has received relatively little attention. This paper is concerned with experimental determination of the flammability limits of LPG- air mixture. The standard procedure suggested by US Bureau of mines has been adopted for the present studies for determining the flammability limit of LPG-air mixture. The lower flammability limit (LFL) is found to be 1.81% and upper flammability limit (UFL) is 8.86% of LPG for upward propagation of flame. Whereas, for downward propagation of flame, the LFL and UFL are 1.87 and 7.69% of LPG, respectively. The nitrogen dilution effects on the flammability limits have been explored, which is presented on a flammability limit plot. It is believed that these data will be very useful for developing fire extinguishers and other combustion devices. (C) 2002 Elsevier Science Ltd. All rights reserved.