This invention relates to a method for detecting pancreatic cancer using novel tumor markers. Specifically, the invention provides a method for detecting pancreatic cancer comprising measuring the presence or an amount of a polypeptide having an reactivity of binding via an antigen-antibody reaction to an antibody against CAPRIN-1 protein in a sample separated from a subject, and to a reagent or kit for detecting pancreatic cancer comprising a CAPRIN-1 protein or a fragment thereof, an antibody against the same, or a polynucleotide encoding the same.