2 completamente aleatorizado. Como resultado del analisis de varianza, se determino que dentro de los rangos de con- tenido de humedad y direccion de medicion estudiados, este ultimo se presenta como factor significativo, explicando el 95% de la variabilidad total observada. De hecho, la variacion del contenido de humedad entre 0 y 15%, conlleva a valores de veloci- dad de propagacion promedio de 1.644 m/s y 2.130 m/s para las direcciones tangencial y radial, respectivamente. Los resulta- dos de este trabajo permiten concluir que al momento de realizar una evaluacion mediante ultrasonido en estructuras en servi- cio, principalmente se debe considerar la direccion de medicion como un factor determinante en el estudio; sin embargo, la e- fectividad de aplicacion de esta tecnica requiere de otros trabajos complementarios que consideren la propagacion en planos mixtos de la madera. Este estudio se llevara a cabo proximamente. Palabras clave: Pinus Radiata, ultrasonido, diseno factorial. ABSTRACT This study was carried out in order to analyse the ultrasound technique as an alternative form of assessing the structural state of different wooden buildings. This work studies the effect and relative importance of measurement direction and moisture content on ultrasound speed in wood. Radiata pine wood samples were subjected to 1 MHz longitudinal ultrasound pulses. A 2 2 factorial design was run in a completely random experiment. Measurement direction was the significant factor, as shown by the analysis of variance, explaining 95% of total ultrasound velocity variability. Average tangential and radial propagation speeds were between 0% and 15% moisture content, 1644 m/s and 2130 m/s, respectively. The results of this study showed that wave propagation direction is the most important factor during wood structure ultrasound evaluation. Future studies with combined planes are un- derway.