Mass transfer coefficients at the gas-liquid interface were investigated for different flow configuration systems, a stirred tank reactor and a gravity pipe. Computational fluid dynamics (CFD) simulations were performed for all tested experimental conditions. Since a poorly soluble gas (oxygen) was used, the overall mass transfer coefficient was clearly correlated to the hydrodynamic conditions in the liquid phase. However, a generic correlation between averaged interfacial liquid velocity and mass transfer coefficients was not found for both geometries. Finally, the averaged turbulent kinetic energy (TKE) ki over bar at the interface is the most relevant parameter that was correlated to the mass transfer coefficient for both systems. The same relationship between oxygen mass transfer coefficient K- L,K-O2 and TKE (KL,O2=0.037+11.610x106ki over bar 2,46) can be applied for the two geometries investigated.