This work presents a numerical and experimental approach in order to predict the fire resistance of perforated cellular wooden slabs. The wooden slabs are lightweight, easy installation, excellent architectural, thermal and acoustic characteristics. However, its high vulnerability to fire, requires their behaviour assessed accurately. Wood material produces a surrounding char layer in depth, when exposed to fire resulting in a reduced residual section. For this purpose, different cellular wooden slabs, with the bottom surface perforated, including different small and large rectangles and circles, were tested and submitted to fire exposure. The experimental study was conducted in laboratory in accordance with European standard (EN1365-2, 2012), using a fire resistance furnace which complies the requirements of European standard (EN1363-1, 2012). Also a three-dimensional thermal and transient numerical model, using a finite element program Ansys®, was validated with experimental tests at real scale. The numerical and experimental results show good agreement. The numerical model can easily be adjusted for other constructive solutions, in order to facilitate fire safety tests, in buildings with wooden slabs used in floors or in ceilings applications.