This study delves into the ramifications of manufacturing-induced defects, particularly porosities, on the dynamic behavior of functionally graded material (FGM) beams. These defects possess considerable potential to alter the structural integrity and performance of such elements. The principal objective of this investigation is to examine the free vibration properties of FGM beams incorporating porosities. A power-law formulation is employed to delineate the distribution of Young’s modulus across the beam thickness, while Poisson’s ratio is held constant. Diverse configurations of porosity distribution are thoroughly explored, and the fidelity of the proposed model is rigorously evaluated through comparative assessments. Additionally, this research endeavors to elucidate the effects of variations in porosity distribution rate, power-law index, and thickness ratio on the fundamental frequency of the beams.