The EuroHOPE very low birth weight and very low for gestational age infants study aimed to measure and explain variation in mortality and length of stay (LoS) in the populations of seven European nations (Finland, Hungary, Italy (only the province of Rome), the Netherlands, Norway, Scotland and Sweden). Data were linked from birth, hospital discharge and mortality registries. For each infant basic clinical and demographic information, infant mortality and LoS at 1 year were retrieved. In addition, socio-economic variables at the regional level were used. Results based on 16 087 infants confirm that gestational age and Apgar score at 5 min are important determinants of both mortality and LoS. In most countries, infants admitted or transferred to third-level hospitals showed lower probability of death and longer LoS. In the meta-analyses, the combined estimates show that being male, multiple births, presence of malformations, per capita income and low population density are significant risk factors for death. It is essential that national policies improve the quality of administrative datasets and address systemic problems in assigning identification numbers at birth. European policy should aim at improving the comparability of data across jurisdictions. Copyright © 2015 John Wiley & Sons, Ltd.