In research projects focussed on children and families, information about children is often gathered via a single parent, often the child's mother or female caregiver. For many such studies, there are valid scientific reasons why involvement of the child's father or male caregiver is also important. For cohort studies, which follow families over time, early recruitment and ongoing engagement of fathers can be particularly important. However, recruiting and engaging fathers to such studies can be challenging, especially if fathers and mothers do not live together. As a result fathers are widely under-represented in such research. A scoping review of recruitment and engagement methods suggests that involving fathers may require a different approach to that used for mothers. This study seeks to review how fathers are recruited and engaged in the ALSPAC G2 cohort, to propose tailored recommendations to improve recruitment and engagement and test the feasibility and acceptability of the revised, tailored approach with participants and research staff. The general learning from this process is expected to be relevant to many similar research projects.