Circulating levels of the proinflammatory cytokines interleukin‐6 (IL‐6), IL‐8, and tumor necrosis factor‐α (TNF‐α) were measured in 13 children with autoimmune hepatitis (AIH) (seven with type 1 and six with type 2). In untreated children with type 1 AIH, TNF‐α, IL‐6, and IL‐8 levels were elevated when compared to those of healthy controls (p < 0.005, p < 0.02, p = 0.06, respectively), whereas in children with type 2 AIH, cytokine levels were normal in all except one sample. A significant decrease in circulating IL‐6, IL‐8, and TNF‐α was observed when patients were evaluated during a subsequent remission. We found no significant correlation of cytokine levels with alanine aminotransferase (ALT) activity, total serum γ‐globulins, or prothrombin activity. In patients with cirrhosis, serum IL‐8 and IL‐6 levels were higher (significantly in the case of IL‐8) than those of patients without cirrhosis. In conclusion, activation of the in vivo production of the proinflammatory cytokines IL‐6, IL‐8, and TNF‐α appears to be associated with type 1 but not with type 2 AIH.