This pilot trial aimed to evaluate the feasibility, acceptability, and preliminary efficacy of Collaborative Healthcare Encounters with Caregivers (CHEC), a checklist-based intervention designed to enhance caregiver participation in older adults' primary care visits. N = 52 older patient-caregiver dyads were randomized to CHEC (n = 28) or usual care (n = 24). Visits were audio-recorded and analyzed according to a standardized coding procedure. Post-visit questionnaires assessed caregivers' perceptions of the checklist, efficacy in primary care interactions and knowledge of relevant resources. CHEC caregivers perceived the checklist to be useful and easy to complete. Visit duration was comparable in CHEC and usual care visits (M = 31.4 minutes vs. M = 31.8 minutes; p = .55), but CHEC visits allocated a greater proportion of time to discussing caregivers' concerns about the patient (32.9% vs. 18.9%; p = .04). CHEC caregivers reported slightly higher post-visit self-efficacy and significantly greater knowledge of relevant resources. Findings suggest CHEC's potential as a clinically feasible intervention for primary care. Clinical Trials Identifier: NCT04946942.