The possibility of using real time holographic interferometry (HI) to detect defects in printed circuit boards has been explored. Initial results indicate that real time HI can reveal some of the most common PC board defects such as solder crack, desoldered junctions, trace separation and components snipped at the soldered joints. In this study, thermal stressing was used as the probe since it did not require the board to be powered, and hence, allows the PCB test mounts to be simple. Our studies also indicate that holographic interferometry can detect and pinpoint more than one defect if present in the field of view.