There is growing awareness of sudden unexplained death in alcohol misuse (SUDAM) in which there is no obvious cause of death, no evidence of acute alcohol toxicity or alcoholic ketoacidosis, and the heart is morphologically normal. This study describes the characteristics of a cohort with SUDAM from a tertiary cardiovascular referral center and compares the findings with those of individuals who died from sudden arrhythmic death syndrome (SADS). Cases in this retrospective cross-sectional study were identified from a database of referrals to our center spanning approximately 40 years. Cases with recorded heavy use of alcohol and non-alcohol users were selected, then limited to those with SUDAM or SADS aged 16 to 64 years. 62 cases of SUDAM and 41 cases of SADS were identified. The SUDAM group were older than the SADS group; mean age 35.8 years and 27.7 years respectively (P=0.0002). There was also a higher incidence of significant psychiatric illness in SUDAM (19.7%) than SADS (2.4%) cases. Post mortem liver examination was more likely to reveal heavy livers in SUDAM than SADS (2196.1g and 1572.4g respectively; P=0.0033) and more fatty liver change (24.2% and 2.4%). SUDAM tends to occur in individuals who are older and have heavier livers than those with SADS. Psychiatric illness is also more common. SADS, unlike SUDAM, is often associated with heritable channelopathies that may affect surviving family members. Therefore, differentiating between SUDAM and SADS identifies families likely to benefit from screening for these mutations, thus preventing further sudden arrhythmic deaths.