Background: Although IgE is well known for its role in atopic disease and parasitic infections, new evidence suggests that IgE is a pleotropic immunoglobulin molecule with many functions. We and others have recently shown that IgE possesses anti-viral activity, and can elicit anti-cancer effects. Others have recently proposed that patients with allergy/atopy have decreased incidence of pancreatic cancer. We therefore investigated serum levels of IgE and its low affinity receptor, soluble CD23 (sCD23), in patients with pancreatic carcinoma. Methods: Twelve patients were evaluated for pancreatic cancer by imaging (CT, MRI, EUS) with subsequent biopsy or surgery. Serum samples were collected prior to any intervention. Serum IgE and sCD23 levels were measured by enzyme linked immunosorbant assay (ELISA) in a blinded manner. Serum obtained from fifteen healthy volunteers served as controls. Patients and controls did not have any history of atopy or parasitic infections. IgE and sCD23 levels are expressed as IU/mL and U/mL, respectively (mean +SE) with significance between groups set at p < 0.05 (Student’s t-test). Results: Serum levels of IgE were significantly elevated in patients with pancreatic cancer (148+45 IU/ml), compared with controls (30+6.3 IU/ml) (p=0.022). Serum levels of sCD23 were also significantly elevated in patients with pancreatic cancer (2.82+0.91U/ml), compared with controls (1.42+0.22 U/ml)(p=0.006). Conclusions: Serum levels of IgE and sCD23 were significantly increased (5-fold and 2-fold, respectively) in patients with pancreatic cancer, compared with controls. These data suggest that IgE and sCD23 may serve as useful biomarkers for patients with pancreatic cancer, and may be important in the immune response to this disease.