In 79 children treated in the Sophia Children's Hospital in Rotterdam because of imminent limping due to congenital dislocation of the hip, the contribution of screening tests by physicians of Infant Health Centres to the timely discovery of this disease was examined. When both limitation of abduction of the hip and difference in length of the legs are examined 6 times in the period of 1-8 months of age, the following results in relation to children not or less well screened may be expected: The risk of discovery of the disease at an age when surgery is not excluded, is reduced to one-third. As a result of the shorter delay between discovery and treatment in practice the risk of having to undergo surgery is halved. The risk of discovery at an age when osteotomy according to Salter is required, is nil. In practice the risk of having to undergo osteotomy is reduced to one quarter. Lowering the frequency of the screening tests reduces the contribution. Examination of just limitation of abduction of the hip also appears to reduce the contribution.