BACKGROUND: The Thompson encephalopathy score is a clinical score to assess newborns suffering from perinatal asphyxia. Previous studies revealed a high sensitivity and specificity of the Thompson encephalopathy score for adverse outcomes (death or severe disability). Because the Thompson encephalopathy score was developed before the use of therapeutic hypothermia, its value was reassessed. OBJECTIVE: The purpose of this study was to assess the association of the Thompson encephalopathy score with adverse short-term outcomes, defined as death before discharge, development of severe epilepsy, or the presence of multiple organ failure in asphyxiated newborns undergoing therapeutic hypothermia. METHODS: The study period ranged from November 2010 to October 2014. A total of 12 tertiary neonatal intensive care units participated. Demographic and clinical data were collected from the "PharmaCool" multicenter study, an observational cohort study analyzing pharmacokinetics of medication during therapeutic hypothermia. With multiple logistic regression analyses the association of the Thompson encephalopathy scores with outcomes was studied. RESULTS: Data of 142 newborns were analyzed (male: 86; female: 56). Median Thompson score was 9 (interquartile range: 8 to 12). Median gestational age was 40 weeks (inter quartile range 38 to 41), mean birth weight was 3362 grams (standard deviation: 605). All newborns manifested perinatal asphyxia and underwent therapeutic hypothermia. Death before discharge occurred in 23.9% and severe epilepsy in 21.1% of the cases. In total, 59.2% of the patients had multiple organ failure. The Thompson encephalopathy score was not associated with multiple organ failure, but a Thompson encephalopathy score >= 12 was associated with death before discharge (odds ratio: 3.9; confidence interval: 1.3 to 11.2) and with development of severe epilepsy (odds ratio: 8.4; confidence interval: 2.5 to 27.8). CONCLUSION: The Thompson encephalopathy score is a useful clinical tool, even in cooled asphyxiated newborns. A score >= 12 is associated with adverse outcomes (death before discharge and development of severe epilepsy). The Thompson encephalopathy score is not associated with the development of multiple organ failure.