Old yellow enzymes are able to catalyze asymmetric C=C reductions. A mediated electroenzymatic process to regenerate the NADPH in combination with an old yellow enzyme was investigated. Due to the fact that the overall process was affected by a broad set of parameters, a design of experiments (DoE) approach was chosen to identify suitable process conditions. Process conditions with high productivities of up to 2.27 mM/h in combination with approximately 90% electron transfer efficiency were identified.