Background <p>Promotion of community-based activities that support individuals with cognitive decline, including mild cognitive impairment (MCI) and early-stage dementia, is a public health priority requiring innovative, non-pharmacological interventions. This protocol describes a multicenter dual cross-over randomized controlled trial designed to evaluate the effects of social crafting, a community-based handmade craft intervention, on self-efficacy and multiple health domains among older adults with MCI and early-stage dementia.</p> Methods <p>A dual cross-over randomized controlled trial was designed with two cohorts: older adults aged 60 and over with MCI (<i>n</i> = 38, completed) and early-stage dementia (<i>n</i> = 40, ongoing). Participants undergo a 9-week, 90-minute weekly handmade craft program, delivered in collaboration with a corporate partner. Craft difficulty is adjusted by specialized instructors to suit each participant’s level, considering their cognitive characteristics. Each participant completes both intervention and control phases in a randomized sequence, serving as their own control. The primary outcome is self-efficacy; secondary outcomes include social engagement, mental health, cognitive function, and functional health. Assessments occur at baseline, post-intervention, and post-control. Mixed-effects models will account for within-subject variability and carryover effects.</p> Discussion <p>Findings from this trial will inform the development of scalable, community-based craft interventions that enhance self-efficacy, social engagement, and overall well-being among older adults with MCI and early-stage dementia. The results will guide the implementation of inclusive, sustainable lifelong learning programs that foster confidence, lifelong learning, and social participation, ultimately contributing to improved health and quality of life in this population.</p> Trial registration <p>These studies were registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) on March 3, 2025: UMIN000057189 (for older adults with mild cognitive impairment, <ExternalRef> <RefSource>https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi? recptno=R000065337</RefSource> <RefTarget Address="https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi? recptno=R000065337" TargetType="Other" /> </ExternalRef>) and UMIN000057191 (for older adults with early-stage dementia, <ExternalRef> <RefSource>https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi? recptno=R000065375</RefSource> <RefTarget Address="https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi? recptno=R000065375" TargetType="Other" /> </ExternalRef>).</p> Trial registrations <p>UMIN000057189: Older adults with mild cognitive impairment.</p>