Little is known about how mental health services consider the parenting role and the well‐being of children when assessing parents with acute mental illness. This paper investigated how crisis mental health services addressed child well‐being in the Wellington region, New Zealand. This mixed‐method case study included: (i) an audit of the electronic clinical records of all adults presenting to the crisis assessment team; (ii) interviews with 22 key informants; and (iii) a documentary review. We found that data about children were not systematically collected. Less than half of (49 of the 104) the records of patients who were parents included information on their child's well‐being; only six (6%) contained a specified plan for action. The focus for services was the adult patient. Key informants were unclear about their role. They identified inadequate training and institutional support, inflexible funding models and limited availability or inappropriateness of referral services as problems. They saw a need for children to become more visible, for collaborative working to improve the use of existing services and for new funding models, resources and roles. Existing national policy documents contained little guidance and no practice guidelines were in use. These were lost opportunities to improve support for the parenting role and promote child well‐being.