In 10,108 babies born to gypsy parents, birth weight, birth length and gestational age are compared with a national reference sample, taking into account maternal education, age, and birth interval. The gypsy babies tend consistently to be smaller, and this difference is attributable to the circumstances in which the gypsies live as well as the poorer maternal education. There appears to be a vicious circle—poor hygiene and living conditions adversely affect birth size, which in turn puts the child at a disadvantage in terms of survival, health and development.