BACKGROUND: Intergenerational friendship is a friendship which occurs between differing generations of older and younger adults. Intergenerational friendship as a research topic has received little attention from sociologists of ageing, despite the cultural turn. This study set out to explore and understand intergenerational friendships from the perspective of the older friend. METHOD: This research took a qualitative approach using Constructivist Grounded Theory methodology. Twenty-three people aged 65 and over were interviewed in Ireland to attain rich narrative accounts and observational memos were generated. FINDINGS: Intergenerational friendship formed part of the process that shaped the older friends' approach to ageing in their everyday lives (micro level), being influenced by stereotyping and commonly held understandings of ageing and older people in contemporary society (macro level). Engaging with intergenerational friends was congruent with the meaning these participants attached to 'being old' or 'being young' and how adults 'should' be in older and in younger age. DISCUSSION: For the older adults in this study, ageing is about performance - how they perform as older adults in their pursuits or interests - and not about chronological age. Intergenerational friendship is an integral part of this strategy for doing ageing in a meaningful yet mundane (everyday, taken for granted), way.