BACKGROUND: There is a current emphasis on 'progressive universal' delivery of the UK child health programme, with a core universal service complemented by enhanced support provided according to need. In Scotland, a three-category indicator of need, the 'Health Plan Indicator' (HPI) is used to identify children requiring enhanced support from the child health programme to facilitate this. METHODS: Routine child health programme and hospital delivery records for a cohort of 36 871 Scottish children were used to explore the factors associated with being identified as requiring enhanced child health programme support using multilevel logistic regression modelling. RESULTS: The following factors were all independently associated with an increased likelihood of being assessed as requiring enhanced support: (i) deprivation; (ii) young maternal age, maternal smoking and drug misuse; (iii) a previous stillbirth; (iv) prematurity; (v) being small for gestational age; (vi) no breastfeeding, admission to a special care baby unit; and (vii) medical, social or developmental concerns about the baby. There was a tendency for children living in areas with higher Health Visitor staffing levels to be more likely to be assessed as requiring enhanced support but this effect was not statistically significant. There was significant residual variation between areas in the likelihood of children being assessed as requiring enhanced support. DISCUSSION: This study suggests Health Visitors take a complex range of factors into account when assessing which children require enhanced support from the child health programme. Health Visitors' workload may influence the likelihood of them identifying children as requiring enhanced support but this requires further clarification. There are clear differences between areas in allocation of the different HPI categories. Further work is required to explore the relationship between being identified as in need of enhanced support, the care actually provided to children, and their outcomes.