There is little information available regarding the role of inflammatory cells and cytokines in the pancreatic tissue during acute interstitial pancreatitis. The single intravenous application of dibutyltin dichloride (DBTC) induces a pancreatitis in rats with a dosage dependent course. We analyzed the infiltrating leukocytes and the cytokine expression profile in the experimental model of DBTC-initiated mild interstitial pancreatitis during a time course of 4 weeks. Macrophages dominated among the infiltrating inflammatory cells detected by immunohistochemistry. The expression of IL-1β, IL-10, and TGFβ1 was shown to be elevated 24 hours after onset of pancreatitis reaching a maximum during the first week. Positive immunostaining of IL-1β, IL-10, or TGFβ1 was not restricted to infiltrating leukocytes but was found to various degrees in pancreatic cells. Transcripts of collagen type 1 reached high levels in the first week, but were down regulated thereafter. There was no significant expression of IL-2, IL-2 receptor, IL-4, TNFα, or IFNγ. Our data show that the experimental interstitial pancreatitis was characterized by macrophage infiltration accompanied by elevated cytokine expression that lasted longer than the visible morphologic lesions. These inflammatory processes might create the environment that makes the pancreas more susceptible to further damaging effects.