We performed a survey on socioeconomic factors in 27 studies of children's environmental health funded by EU FP4 and FP5. Parental education was the most common measure (74%). Socioeconomic factors were predominantly considered as confounder (74%) and less often as effect modifier (33%) or independent variable (37%). The awareness of the need to study the impact of socioeconomic factors further seems to have increased in recent years.