Background: The aim of this study was to identify risk factors for immunoglobulin resistance, including clinical symptoms such as arthritis and the pH of intravenous immunoglobulin. Methods: The data of children with Kawasaki disease who had received immunoglobulin were evaluated. Data regarding the brand of immunoglobulin administered were abstracted from the pharmacy records. Results: Eighty consecutive children with Kawasaki disease were evaluated (Mdn age = 28 months, 66% male). The prevalence of immunoglobulin resistance was 30%. Arthritis was a presenting symptom in the acute phase of Kawasaki disease in 8% (6/80, all male) and was seen in significant association with immunoglobulin resistance in comparison to those without arthritis (16.7% vs. 0.2%, p = 0.008). Next, the immunoglobulin brand types were divided into two groups: the relatively high pH group (n = 16), including Carimune (pH 6.6 -0.2), and the low pH group (n = 63), including Gamunex (pH 4-4.5) or Privigen (pH 4.6-5). Overall, no significant difference in immunoglobulin responsiveness was found between the low pH and the high pH groups (73% vs. 56%, p = 0.193), although the low pH group showed a trend toward a larger decrease in erythrocyte sedimentation rate ( p = 0.048), lower steroid use ( p = 0.054), and lower coronary involvement ( p = 0.08) than those in the high pH group. Conclusions: Children presenting with arthritis in the acute phase of Kawasaki disease may be at risk for immunoglobulin resistance.