Objective: To characterize the clinical presentation and outcomes of Kawasaki disease (KD) in infants 10 days (50% vs 7.4%, P = 0.043). Conclusion: Our data show that despite treatment in the first 10 days of illness, infants < 6 months of age in Latin America have a higher risk of developing a coronary artery aneurysm. Delay in the diagnosis leads to larger coronary artery aneurysms disproportionately in these infants. Thus, suspicion for KD should be high in this vulnerable population.