Objectives: Kawasaki disease (KD) is a systemic vasculitis primarily affecting children who are <5 years old. Intravenous immunoglobulin (IVIG) is the standard therapy for KD. However, many patients with KD still show poor response to initial IVIG treatment. This study was conducted to investigate the risk factors for initial IVIG treatment failure in KD. Methods: Children who met KD diagnosis criteria and were admitted for IVIG treatment were retrospectively enrolled for analysis. Patients were divided into IVIG-responsive and IVIG-resistant groups. Initial laboratory data before IVIG treatment were collected for analysis. Results: A total of 131 patients were enrolled during the study period. At 48 h after completion of initial IVIG treatment, 20 patients (15.3%) had an elevated body temperature. Univariate analysis showed that patients who had initial findings of high neutrophil count, abnormal liver function, low serum albumin level (≤2.9 g/dL) and pericardial effusion were at risk for IVIG treatment failure. Multivariate analysis with a logistic regression procedure showed that serum albumin level was considered the independent predicting factor of IVIG resistance in patients with KD (p = 0.006, OR = 40, 95% CI: 52.8–562). There was no significant correlation between age, gender, fever duration before IVIG treatment, haemoglobin level, total leucocyte and platelet counts, C-reactive protein level, or sterile pyuria and initial IVIG treatment failure. The specificity and sensitivity for prediction of IVIG treatment failure in this study were 96% and 34%, respectively. Conclusion: Pre-IVIG treatment serum albumin levels are a useful predictor of IVIG resistance in patients with KD. [ABSTRACT FROM AUTHOR]