Health is routinely considered in strategic environmental assessment (‎SEA)‎ and environmental impact assessment (‎EIA)‎, following requirements of European Union directives and the Protocol on Strategic Environmental Assessment to the Convention on Environmental Impact Assessment in a Transboundary Context (‎Espoo Convention)‎. Policy-makers and other sources report that these assessments mostly adopt a biophysical perspective and that few cases consider or define health in a manner which is consistent with the WHO Constitution, by considering the wider social, economic, behavioural and institutional aspects of health. This systematically conducted review of over 333 SEA and EIA cases in the WHO European Region shows that while about 80% of assessments pursue a narrow, biophysical interpretation of health, around 10% consider wider determinants when defining health, and another 10% consider wider determinants of health in the actual assessment. Twelve case studies are presented, literature is reviewed and implications for practice are considered.