This article explores concerns about, and experiences of, ageing amongst men during the early years of fatherhood. Despite acknowledgement of the interconnectivities between age and gender, accounts of ageing masculinity have been relatively overlooked, particularly in relation to younger and middle-aged men's perceptions of ageing. However, some evidence suggests that despite a general trend towards increasing longevity, anxiety about ageing is occurring at ever younger ages. Drawing on data from a qualitative longitudinal study, this issue is considered here through a parenting lens in light of the wider social trend towards delayed fatherhood. The article focuses on the experiences of men aged 29-54 whose accounts indicate widespread concern about ageing, regardless of their actual chronological age. The analysis foregrounds how these concerns are linked to the continuing association between fathering and physical activity, which highlights the need to consider the implications of advanced paternal age for father-child relationships.