The purpose of this article is to analyse with longitudinal data from Norway the caring activities of sons and daughters who were the primary care-giver to a parent aged 80 or more years. The study sample consists of the 227 offspring care-givers in the Larvik study, which examined the illnesses and disabilities and the informal and formal care received until their deaths of all those aged 80 or more years in the town's population in 1981. Prospective and retrospective data were collected from that year about the health, functional losses and formal service utilisation of the older people. After the death of an older person in the study, the next-of-kin was interviewed about the informal care provided by relatives and friends during the same time span. The sequences and content of the care-giving activities differed little for son or daughter care-givers, except during a short escalation phase. The average duration of informal home care was shorter for sons than for daughters, primarily because a minority of the daughters had very long care-giving careers. The duration of the care recipients' stays in acute or long-term care institutions before death did not differ by the gender of the carer. Compared with many earlier studies, few gender differences in offspring care-giving activities were found. The findings suggest that the potential of sons to provide informal care to frail older parents is underestimated in modern societies.