An example of the rare papillary cystic tumor of the pancreas was diagnosed cytologically by aspiration of the primary neoplasm. Subsequently, it metastasized, proving its low-grade malignant behavior. Diagnostic cytomorphologic features included abundant straight and branched papillary tissue fragments, and uniform, pale nuclei with folds or grooves. Although the primary tumor had a typical histologic appearance, metastases demonstrated increased nuclear pleomorphism and hyperchromasia, bizarre tumor giant cells, and an increased mitotic rate. Vimentin was diffusely positive, whereas neuron-specific enolase and somatostatin were focally and weakly reactive. Neurosecretory and zymogen granules were absent ultrastructurally. By flow cytometric study, the tumor was aneuploid (DNA Index = 1.3).