This study presents the development processes of a high-efficiency two-output flyback-converter. The detailed design phases are presented together with encountered design obstacles, limitations and the methods to overcome them. Despite their widely use in industry, studies on high-efficient flyback converter design still remains a need. Most of the flyback converters are designed with multi outputs for their various input voltages. This study firstly describes the preliminary design stages, modeling studies and definition of magnetic and electronic components and PCB design processes followed by a prototype manufacturing. Modelling study is conducted in MATLAB/Simulink environment, and PCB design is realized in Altium Designer Software. Prototype is tested and its performance parameters are recorded. It is seen that the performance values are good agreement with those of design objectives.