Mild cognitive impairment (MCI) is a high-risk state for dementia, marked by cognitive decline with preserved daily functioning. Combined physical and cognitive activity (PA+CA) programs show promising benefits for MCI patients. Involving adult children through intergenerational approaches may enhance participation and impact, yet little is known about tailoring such programs to both generations’ needs. This study aimed to (1) identify cognitive, physical, and psychosocial challenges experienced by MCI patients, and (2) explore the needs, preferences, barriers, and facilitators regarding participation in an intergenerational PA+CA program. A mixed-methods design combined a scoping review of 45 studies with eight semi-structured interviews involving eight MCI patient–adult child dyads. Results highlight challenges such as memory loss, fatigue, social withdrawal, and a desire for meaningful, safe, and structured activities. Barriers included overload, physical limitations, and time constraints; facilitators involved routine, emotional support, and family connection. Findings offer guidance for designing effective intergenerational PA+CA programs.