It has been suggested that screening for impairment in early childhood may cause anxiety to parents. Using self-administered questionnaires, we studied the attitudes and concerns of parents of infants aged 6 months and 8-9 months. Parents were randomly allocated to one of two groups. One group completed the second questionnaire after the 8-month assessment routinely performed by health visitors, and the other group completed the second questionnaire before the assessment. We showed changes in attitude and concerns over the 2-3 month period, but these were not related to the assessment. It appeared that particular concerns and anxieties were not resolved by a recent contact with a health visitor, although a high proportion of mothers stated that they found the assessment reassuring. There was some evidence of a lack of appreciation, both of the purpose of the tests and of the implication of test failure. Screening tests performed by health visitors at an age of 8 months do not appear to generate undue anxiety in parents. However, as many of the tests used are of doubtful validity, a review of the purpose and content of this early health visitor assessment is needed.