Useful microemulsions have corrosion inhibitors in the internal phase and an external phase and at least one surfactant that helps define the emulsion. The corrosion inhibitor itself may have its pH adjusted so that it also serves the role of surfactant. The corrosion inhibitors form microemulsions with particle or droplet diameters of about 10 to about 300 nm. The microemulsions may be oil-in-water, water-in-oil or bi-continuous.