For naturally ventilated buildings (NVB) located in the tropical regions, thermal comfort (TC) prediction based on predicted mean vote (PMV) standard has shown some deviations from the observed results. Hot and humid environmental conditions throughout the year and personal adaptation could have an effect on expectation and perception about TC. Through an extensive field survey conducted in residential buildings in Indonesia, 525 sets of data had been gathered. The data analysis revealed that the PMV equation had predicted warmer thermal perception as compared to what people actually felt. Interestingly, it was observed that under hot and humid tropical climate, people indicated preference to cooler environment as compared to what the neutral temperature has shown. The study also investigated the occupant's adaptive control preferences in creating a more thermally comfortable living environment. The reciprocal effects of occupant's thermal perception and behavioural adaptation were explored. In tropical free-running buildings where the air temperature and humidity might not be modified easily without mechanical means, the people seemed to prefer higher wind speed. (C) 2004 Elsevier B.V. All rights reserved.