With a large baby-boomer generation entering mid-later life in the United Kingdom, and families spanning across multiple generations, understanding how individuals support multiple generations is of increasing research and policy significance. Data from the British 1958 National Child Development Study, collected when respondents were aged 55, are used to examine how mid-life women and men allocate their time to support elderly parents/parents-in-law and their own adult children in terms of providing grandchild care, and whether there is a trade-off in caring for different generations. Binary logistic and multinomial regression models distinguish between individuals supporting multiple generations, only one generation or none. One-third of mid-life individuals are ‘sandwiched’ between multiple generations, by having at least one parent/parent-in-law and one grandchild alive. Among them, half are simultaneously supporting both generations. Caring for grandchildren increases the probability of also supporting one's parents/parents-in-law, and vice versa. More intense support for one generation is associated with a higher likelihood of supporting the other generation. Good health is associated with caring for multiple generations for men and women, while working part-time or not at all is associated with such care provision for women only. Facilitating mid-life men and women in responding to family support demands whilst maintaining paid employment will be critical in fostering future intergenerational support.