Statins (HMG-CoA reductase inhibitors) may decrease inflammation in postacute Kawasaki disease (KD) complicated by coronary artery aneurysm (CAA) and promote vascular remodeling. There are limited data on their safety in young children. Twenty patients with CAAs after KD (median CAA z-score = +25) were treated with 5/10 mg atorvastatin daily for a median of 2.5 years (range 0.5-6.8) starting at a median of 2.3 years (range 0.3-8.9) after acute KD (median age 9.3 years [range 0.7-14.3]). Compliance with treatment was excellent: only one patient reported minor side effects (joint pain, no change in medication). Average total cholesterol before atorvastatin was 3.73 ± 0.84 mmol/L and after atorvastatin was 3.21 ± 0.46 mmol/L (relative decrease -14 %, p = 0.02); low-density lipoprotein cholesterol was 1.99 ± 0.76 mmol/L before and only 1.49 ± 0.27 mmol/L after (relative decrease -20 %, p = 0.04); high-density lipoprotein was 1.39 ± 0.36 mmol/L before and 1.30 ± 0.27 mmol/L after (relative decrease -4 %, p = 0.35); and triglycerides were 0.71 ± 0.28 mmol/L before and 0.71 ± 0.18 mmol/L after (relative decrease -5 %, p = 0.38). Nine of 20 patients (45 %) experienced at least 1 episode of hypocholesterolemia (total cholesterol <3.1 mmol/L), and 2 patients required atorvastatin dose lowering. Transient mild increase of liver enzymes (aspartate aminotransferase/alanine aminotransferase 45-60 U/L) were seen in 7 of 20 (35 %) patients with no patients experiencing more severe increases. Only one patient experienced increased creatine phosphokinase levels (>500 U/L). Serial measurements of age- and sex-specific percentiles of weight (estimated change: 1.4 [2.7] % per year, p = 0.60), height (estimated change: -3.2 [3.2] % per year, p = 0.32), and body mass index (estimated change: 1.0 [2.9] % per year, p = 0.73) showed no association between anthropomorphic growth and atorvastatin treatment. Atorvastatin use in very young children with KD is safe but should be closely monitored.