Several parameters such as mixing time, power consumption and deformation rates have been commonly reported in the literature for the hydrodynamic characterization of shaken flasks. In the present work, flow fields of orbital shaken flasks having different geometries have been experimentally obtained. Conventional, baffled and coiled flasks were tested at constant shaking speed of 150 rpm at which the cultures are grown. Flow fields in terms of turbulence intensity and deformation rate were both determined by means of the Particle Iniage Velocimetry (PIV) technique. Velocity fields are strongly dependent on the flask geometry; in particular, the main flow is confined near the wall for the conventional geometry. In general, large velocity fluctuations are found in the whole flask for the baffled and coiled geometries, while the turbulence intensity is virtually zero at the center region for the conventional flask. The measurement of the average deformation rate indicates that flow obstacles, such as indentations and coiled springs, generate regions with high hydrodynamic stresses promoting the elongation and breakup of bubbles and biomass. Results from this study have been compared with previous studies finding good agreement for the same flask configurations at similar experimental conditions. (C) 2016 Elsevier Ltd. All rights reserved.