Objectives: We set out to determine the causes of death in childhood-onset systemic lupus erythematosus (cSLE)., Methods: The medical records of children aged <18 years who were diagnosed with SLE from 1985 to 2016 in the Division of Nephrology, Department of Paediatrics, Faculty of Medicine, Prince of Songkla University, Thailand, were reviewed., Results: There was a total of 331 patients, 272 girls and 59 boys, of whom 77 (23.3%) died, 28.6% within the first year after diagnosis. Only 29 medical records of the 77 confirmed-death patients were available for evaluation of cause of death; 7 boys and 22 girls, with a mean age at presentation of 10.9±3.1 years. The mean follow-up duration was 4.6±3.7 (range 0.2-12.6) years. The major cause of death was sepsis (n=13 patients with 15 identified organisms, which were Acinetobacter baumannii (9), Escherichia coli (3), Candida albicans (2) and Aspergillosis (1)), followed by acute respiratory distress syndrome (ARDS) (6), severe heart condition (3), acute kidney injury (AKI) (2), chronic kidney disease (CKD) (2) and intracranial haemorrhage (1). Conditions at the time of death were sepsis (25), pneumonia (16), AKI (15), bleeding disorders (11), neurological complications (10), ARDS (10), CKD (4), AKI in addition to CKD (3)., Conclusions: The cause of death in cSLE is usually multi-factorial and it is difficult to assign a single dominant cause. Sepsis was the most common cause of death and, together with sepsis-related organ failure, was the most common condition at the time of death. The most common organism was Acinetobacter baumannii.