OBJECTIVE: To evaluate practice variation in pharmacologic management in the International Kawasaki Disease Registry (IKDR). STUDY DESIGN: Practice variation in intravenous immunoglobulin (IVIG) therapy, anti-inflammatory agents, statins, beta-blockers, antiplatelet therapy, and anticoagulation was described. RESULTS: We included 1627 patients from 30 IKDR centers with maximum coronary artery aneurysm (CAA) z scores 2.5-4.99 in 848, 5.0-9.99 in 349, and ≥10.0 (large/giant) in 430 patients. All centers reported IVIG and acetylsalicylic acid (ASA) as primary therapy and use of additional IVIG or steroids as needed. In 23 out of 30 centers, (77%) infliximab was also used; 11 of these 23 centers reported using it in <10% of their patients, and 3 centers used it in >20% of patients. Nonsteroidal anti-inflammatory agents were used in >10% of patients in only nine centers. Beta-blocker (8.8%, all patients) and abciximab (3.6%, all patients) were mainly prescribed in patients with large/giant CAAs. Statins (2.7%, all patients) were mostly used in one center and only in patients with large/giant CAAs. ASA was the primary antiplatelet modality for 99% of patients, used in all centers. Clopidogrel (18%, all patients) was used in 24 centers, 11 of which used it in >50% of their patients with large/giant CAAs. CONCLUSIONS: In the IKDR, IVIG and ASA therapy as primary therapy is universal with common use of a second dose of IVIG for persistent fever. There is practice variation among centers for adjunctive therapies and anticoagulation strategies, likely reflecting ongoing knowledge gaps. Randomized controlled trials nested in a high-quality collaborative registry may be an efficient strategy to reduce practice variation.