The radiant floor heating/cooling systems are more often used in new designed and modernized buildings, what renewed the interest in the study of the characteristic parameters, which are taking in to account by dimensioning or detailed scientific analyzes of such a systems. Very important and fundamental characteristic parameters for radiant floor are heat transfer coefficients. This article presents the results of experimental research on heated/cooled radiant floor conducted in the laboratory room in the climatic chamber, which aim was to estimate experimentally the values of heat transfer coefficients for the surface of cooled/heated radiant floor. The values of radiant, convective and total heat transfer coefficients were developed on the basis of the amount of heat emitted from the radiant surface and by the use of proper and clearly defined reference temperature depending on the kind of heat transfer coefficient. It was noticed, that the values of heat transfer coefficients for heated/cooled radiant floor, which are commonly used in practice, are overestimated, even in the range of 10-30%. (C) 2013 Elsevier B.V. All rights reserved.