Disclosed is a universal primary-only output current regulation for a flyback converter. A controller determines a peak sense resistor voltage responsive to a desired average output current for the flyback converter during a continuous conduction mode of operation. After a power switch transistor is cycled on, the controller monitors a sense resistor voltage to determine when the sense resistor voltage equals the peak sense resistor voltage. The controller switches off the power switch transistor when the sense resistor voltage equals the peak sense resistor voltage to maintain an average output current for the flyback converter equal to the desired average output current.