Post-stroke cognitive impairment can limit rehabilitation, independence, and quality of life after ischemic stroke. This pilot randomized controlled trial evaluates whether mesenchymal stem cell-derived secretome, given in addition to standard stroke care and rehabilitation, improves cognitive recovery in patients with subacute ischemic stroke. Participants aged 40 to 75 years with ischemic stroke occurring 7 days to 3 months previously and mild-to-moderate cognitive impairment will be randomly assigned in a 1:1 ratio to receive standard care and rehabilitation plus MSC secretome or standard care and rehabilitation without MSC secretome. The primary outcome is the change in the Indonesian version of the Montreal Cognitive Assessment score. Secondary outcomes include quantitative electroencephalography parameters, serum brain-derived neurotrophic factor, serum interleukin-1β, NIHSS, modified Rankin Scale, and adverse events.