Due to their unique characteristics ionic liquids (ILs) have been extensively used as solvents in enzymatic procedures, proving to be advantageous alternatives to conventional organic solvents. The studies of enzyme behavior in ILs have increased exponentially in the last years and oxidoreductases particularly have recently started to be studied. The association of oxidoreductases with IL is very promising due to the large field of application of these enzymes. The materials are very interesting not only from the analytical point of view but also in the biocatalytic perspective. In this review, we discuss the behavior of oxidoreductases in the presence of ILs, the mechanisms involved in this association and the immobilization of oxidoreductases in composite materials with IL. The performance of proteins with peroxidase activity in ILs is also reviewed. Future trends and perspectives related with the development of biocatalytic studies involving oxidoreductases and ILs are also considered.