The growth of 39 children with Silver-Russell syndrome has been followed for 1-13 years. Pregnancy and labor were normal; none of the 61 sibs had the syndrome. Height at referral (mean age 4.6 years) averaged 3.6 SD below the mean and remained at this level during subsequent growth. Bone age averaged 69 percent of normal at referral but caught up by puberty, which occurred at the normal time. Nineteen cases were treated with human growth hormone without lasting effect. There is no clear-cut distinction between the Silver and Russell syndromes; the name should be Silver-Russell. It is likely that some 10 percent of cases have birth weights in the minus 1.5 to minus 2.0 SD range.