Diagnosis of sudden cardiac death (SCD) is the most important forensic practice because of (1) misdiagnosis of extrinsic death as SCD, (2) under-report of unusual (unnatural) death, (3) difficulty in diagnosis by autopsy, histology, and death-scene investigation, (4) difficulty to judge the contribution of accident, violence, psychological stress, over-work, and medical malpractice. Forensic pathologists must precisely diagnose the proximal cause of death and determine the contribution of extrinsic and intrinsic factors, thereby showing fair proof for the legal responsibility of the deceased and concerned party. This article reviews these forensic aspects of SCD with reference cases.