The chrome tanning process is the main method employed to improve the hide stabilization, and chrome tanning in organic solvent medium has been tried by some authors, namely for ovine skins, but the process is not yet clear and fully understood. In recent years the application of image analysis methodologies to bioreactors is widely growing mainly on biomass and materials characterization. In the present work, the use of image analysis was employed to examine chromium penetration during bovine hide tannage in the presence of terpentine. Results showed that the overall chromium penetration rate was considerably faster in the first two minutes, becoming then much slower and linear until completion. Furthermore in the initial stages of penetration the chromium diffused much faster on the flesh that on the grain side of the hide. A second study performed on the flesh side only allowed to determine the chromium flux in the hide.