The mechanobiological aspects of glioblastoma (GBM) pathogenesis are largely unknown. Polycystin-1 (PC1) is a key mechanosensitive protein which perceives extracellular mechanical cues and transforms them into intracellular biochemical signals that elicit a change in cell behaviour. The aim of the present study was to investigate if and how PC1 participates in GBM pathogenesis under a mechanically induced microenvironment. Therefore, we subjected T98G GBM cells to continuous hydrostatic pressure (HP) and/or PC1 blockade and evaluated their effect on cell behaviour, the activity of signalling pathways and the expression of mechano-induced transcriptional regulators and markers associated with properties of cancer cells. According to our data, PC1 and HP affect GBM cell proliferation, clonogenicity and migration; the diameter of GBM spheroids; the phosphorylation of mechanistic target of rapamycin (mTOR), extracellular signal-regulated kinase (ERK) and focal adhesion kinase (FAK); the protein expression of transcription cofactors YES-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ); and the mRNA expression of markers related to anti-apoptosis, apoptosis, angiogenesis, epithelial to mesenchymal transition (EMT) and proliferation. Together, our in vitro results suggest that PC1 plays an important role in GBM mechanobiology.