In this research work, the possibility of defect detection in wood–plastic composites (WPCs) by shearography method has been assessed. Shearography is one of the practical nondestructive test methods that has been commonly used for detecting defects in polymer-based composites. In this experimental work, first, a defect (hole) was intentionally drilled on one side of the extruded WPC and then the shearography test and analysis was performed on it. This preliminary step was performed to evaluate the application of the test and calibration. Subsequently, the injection-molded WPCs with different volume fraction of wood content were assessed via shearography test for detection of the probable defects in their structures. The results indicated that shearography method can be effectively used for defect revelation in wood–plastic composites.