In our study, we determined the optimal flow rate for the osteogenic differentiation of human adipose-derived mesenchymal stem cells (MSC) by applying fluid shear stress that mimics the physiological environment normally experienced by bone progenitor cells in vivo. For this, we first analyzed the porosity of cell substrates with nanofocus-computed tomography as well as their specific permeability at different flow rates. To investigate the effect of controlled application of physiologic fluid shear stress a flow rate of 0.3 ml/min was used to cultivate MSC in a self-developed perfusion bioreactor. Cells were seeded on a three-dimensional macro-porous zirconium dioxide ceramic scaffold (0.3·106 cells/scaffold) and cultivated in standard growth medium (GM)or osteogenic differentiation medium (ODM) under normoxic (21% O2) or hypoxic (5% O2) conditions for a period of 21 days. After cultivation cell viability was examined using MTT assay. Furthermore DAPI staining was used to evaluate cell distribution. Glucose consumption and lactate production were monitored and histological stainings (calcein, alicarin red, Von Kossa) were used to evaluate osteogenic differentiation.