In cardiac surgery, perioperative death in low-risk patients is uncommon, but does occur. Reports on the incidence, cause and circumstances of death in this population are rare. We analyzed the early mortality and cause of death in patients with an additive EuroSCORE≤3 who underwent cardiac surgery between 2001 and August 2009 in Stockholm. We also investigated if death could be considered preventable, and in that case, if it was due to a technical or a system error. Among 3924 low-risk patients, 15 died within 30 days of surgery, and early mortality was 0.38%. Cause of death was mostly cardiac related (11 of 15). Death occurred after hospital discharge in three patients, and was classified as non-preventable in 13 patients. In the remaining two patients, the circumstances leading to death were categorized as due to a system error. A systematic and structured analysis of the circumstances resulting in death in low-risk patients, in addition to traditional morbidity and mortality conferences, have the potential to identify problems and offer improvements in the quality of care.