Non-destructive testing of wood – correlation of ultrasonic and stress wave test results in glued laminated timber members. The paper presents application of selected non-destructive testing techniques – ultrasonic and stress wave methods - for assessment of the physical and mechanical properties of wood. Nondestructive testing is a scientific field related to: identification of mechanical properties and physical parameters of materials and structural members, detecting material defects and discontinuities, measurement of geometrical dimensions without affecting the functional properties of the elements under investigation. The paper provides a short description of selected methods used for non-destructive and quasi non-destructive testing of wood. It also reports on research on the correlation between glued laminated spruce wood properties and parameters of ultrasonic and stress wave propagation The research was carried out with a Sylvatest Trio device, which uses ultrasonic technology and a Fakopp Microsecond Timer device, which uses the stress wave technique.