The authors reviewed the recruitment of stroke-affected sibling pairs using a letter-based, proband-initiated contact strategy. The authors randomly sampled 99 proband enrollment forms (Phase 1) and randomly sampled 50 sibling reply cards (Phase 2). The sibling response rate was 30.6%, for a pedigree response rate of 58%. Of the siblings who replied, 96% authorized further contact. Median time from proband enrollment to pedigree DNA banking, which required 3+ probands, was 134 days.