Objective The aims of the present study were to describe the prevalence of vulnerability in a cohort of newborns, identify the factors that increase the risk of vulnerability and examine whether those who are most vulnerable are receiving home visits. Methods A prospective cross-sectional study was performed using data collected from questionnaires completed by child and family health nurses and obstetric discharge summaries for each mother–baby dyad. Descriptive frequencies and percentages are used to describe the proportions of children who were vulnerable, offered services and had risk factors for vulnerability. Categorical data were compared using Pearson’s Chi-squared analysis. Results In all, 1517 newborns were included in the present study. Of these, 40.5% were identified as vulnerable and 13.9% had two or more risk factors for vulnerability (95% confidence interval (CI) 12–16%). The most common risk factors were biological. Across all newborns, 33.7% were visited at home, and 74.6% of vulnerable newborns were offered a home visit. Children identified as vulnerable were more likely to have a home visit than those who were not (z for 95% CI=1.96; P<0.1). Conclusions Although the high reported prevalence of identified risk needs to be confirmed in further studies, identifying vulnerability allowed the offer of home visiting to be directed towards those most likely to benefit. What is known about the topic? Of the Australian child population, 10–20% are vulnerable to adverse health, developmental and wellbeing outcomes. Vulnerable infants are at a greater risk of becoming vulnerable children, adolescents and adults over the life course. Biological and psychosocial risk factors for vulnerability are well described. Families with the greatest need are often the least likely to access or receive support, and have lower utilisation of preventative health services despite evidence that support in the first few years of life can significantly improve long-term outcomes. What does this paper add? This paper provides a detailed description of vulnerabilities in a cohort of newborns and demonstrates that it is possible to assign risk of vulnerability within existing child and family health services using tools that identify biological and psychosocial risk factors. Identification of vulnerability risk allows prioritisation of services to those with the greatest need. What are the implications for practitioners? It is possible to identify vulnerability risk within child and family health services. This allows those families at risk of future adverse health, developmental and wellbeing outcomes to be prioritised to receive health services and supports.