Recent advances demonstrate a critical yet poorly understood role for the pancreatic stellate cell (PSC) in the pathogenesis of chronic pancreatitis (CP) and pancreatic cancer (PC). Progress in this area has been hampered by the availability, fidelity, and/or reliability of in vitro models of PSCs. We examined whether outgrowth cultures from human surgical specimens exhibited reproducible phenotypic and functional characteristics of PSCs. PSCs were cultured from surgical specimens of healthy pancreas, CP and PC. Growth dynamics, phenotypic characteristics, soluble mediator secretion profiles and co-culture with PC cells both in vitro and in vivo were assessed. Forty-seven primary cultures were established from 52 attempts, demonstrating universal α-smooth muscle actin and glial fibrillary acidic protein but negligible epithelial surface antigen expression. Modification of culture conditions consistently led to cytoplasmic lipid accumulation, suggesting induction of a quiescent phenotype. Secretion of growth factors, chemokines and cytokines did not significantly differ between donor pathologies, but did evolve over time in culture. Co-culture of PSCs with established PC cell lines resulted in significant changes in levels of multiple secreted mediators. Primary PSCs co-inoculated with PC cells in a xenograft model led to augmented tumor growth and metastasis. Therefore, regardless of donor pathology, outgrowth cultures produce PSCs that demonstrate consistent growth and protein secretion properties. Primary cultures from pancreatic surgical specimens, including malignancies, may represent a reliable source of human PSCs. Evidence continues to accumulate implicating the intense desmoplastic reaction common to both chronic pancreatitis (CP) and pancreatic cancer (PC) is not simply a bystander process from a dynamic inflammatory state, but rather represents a complex interplay within the microenvironment responsible for the initiation and maintenance of key pathologic feedback systems. 1 Pancreatic stellate cells (PSCs) appear to represent a critical determinant in the development and maintenance of this desmoplastic microenvironment in pancreatic disease states. 2-4 However, recent investigations have questioned the role of PSCs in cancer. Specifically, depletion of activated PSCs in genetically engineered mouse models of PC has paradoxically demonstrated pro-tumor effects. 5,6 While disparate from prior observations showing the tumor promoting abilities of activated PSCs, 3,7-9 these investigations still implicate an interplay between PSCs, other cells within the tumor microenvironment, and the cancer. 5,6 Given these disparate findings, further investigation into the biology of PSCs in various disease states is essential and necessitates a high degree of experimental standardization. To this effect, an expert panel recently published guidelines regarding PSC isolation, identification, and activation. 10 Human PSCs are most typically isolated via the outgrowth method, whereby direct culture of minced pancreatic s...