Noncovalent protein-DNA interactions are involved in many vital biological processes. In cells, these interactions may take place in the environment of an electric field which originates from the plasma and organelle membranes and reaches strengths of 1 MV/cm. Moreover, protein-DNA interactions are often studied in vitro using an electric field as strong as 1 kV/cm, for example by electrophoresis. It is widely accepted that an electric field does not affect such interactions. Here we report on the first proof that an electric field of less than 1 kV/cm can destabilize the protein-DNA complexes through increasing the monomolecular rate constant of complex dissociation.