We have investigated the effect of two simple sugars, glucose and sucrose, on the extraction of ribonuclease A by AOT-isooctane reversed micelles. Including the sugars at concentrations up to 0.75 M in the feed solution resulted in moderate improvements in the forward transfer efficiency. The greatest effects were seen observed in the backward transfer step where both the protein recovery yield and the activity of the protein were greatly increased. Protein transfer and activity yields were also dependent on the AOT concentration. We suggest that the presence of sucrose, which was solubilized into the reversed micelles, results in preferential hydration of ribonuclease A, reducing the protein-surfactant interactions.