Pancreatic stellate cells (PSCs) play a critical role in the progression of pancreatic ductal adenocarcinoma (PDAC): Once activated by carcinoma cells, PSCs support their proliferation and metastasis. Furthermore, they contribute to the excessive deposition of extracellular matrix proteins in the PDAC stroma, the so-called desmoplastic reaction. So far, absolutely no information is available concerning the expression of ion channels in PSCs. It is known that calcium-activated K⁺ channels K_Ca3.1 are involved in cancer progression and cell migration. We therefore investigated the expression and function of K_Ca3.1 in a human PSC cell line. We revealed the functional expression of K_Ca3.1 by means of Western blot, immunofluorescence and patch clamp analysis. K_Ca3.1-mediated K⁺ currents were identified due to their sensitivity to the activator 1-EBIO and blocker clotrimazole. The impact of K_Ca3.1 channel activity on PSC function was determined by analyzing migration using time-lapse videomicroscopy and by imaging the intracellular Ca²⁺ concentration ([Ca²⁺]_i) in the absence and presence of its blocker TRAM-34. Stimulation with PDAC cell supernatants resulted in higher migratory activity of PSCs which - in contrast to basal migration - was inhibited by TRAM-34. The supernatant from the isolated human PDAC cell line Colo-357 was the most effective stimulator of stellate cell migration. PDAC cell supernatants also caused a rise of [Ca²⁺]_i in PSCs that could be attenuated by K_Ca3.1 blockade. In unstimulated PSCs TRAM-34 did not alter [Ca²⁺]_i. In summary, we showed that K_Ca3.1 channels are crucial for stimulated migration of PSCs, most likely via their impact on [Ca²⁺]_i.