In modern technologies, process variations can be quite substantial, often causing design timing failures. It is essential that those errors be correctly and quickly diagnosed. In this work, we analyze failures caused by the holdtime-violations. We investigate the feasibility of using circuit-timing information to guide the hold-time-fault diagnosis. We propose a novel and efficient diagnostic approach based on timing window propagation. For each identified candidate, our method locates the source of the hold-time violation and determines the most probable defect size. Experimental results indicate that the new method diagnoses hold-time related defects with very good resolution.