The goal of this project was to find empirical evidence in order to confirm former results about the strong incidence of moisture content up to fiber saturation point on the wood combustibility,. even aboye density, one of the most used parameters; and also the lovv or null effect of fire retardants on the combustibility of hard woods, contrary to its effectiveness on light and almost-hard woods. The results showed that although the nispero and chanul woods' had a higher density than the machare wood, when exposed to fire, the last one showed the lowest loss of weight and extinction times. This was explained because of the lower values of moisture content up to fiber saturation point of the machare wood, contrary to the expected performance if its low density was considered. The results showed that the application 'of fire retardants had no significative effects on combustibility of hard woods such as nispero, suggesting additional alternatives of management and protection of these woods against fire taking into account physical rather than chemical parameters.