Poor light outcoupling efficiency is one of the main issues in Organic light-emitting diodes (OLEDs). A significant fraction of power is trapped in the high index layers as waveguided modes or lost at the metal cathode surface as plasmonic mode. Internal periodic corrugation inside OLEDs is a promising approach to extract waveguided and plasmonic modes, which can be diffracted back to the air cone to enhance the outcoupling. We develop a general computational framework to simulate the light emission from corrugated OLEDs, based on scattering matrix theory and Maxwell’s equations in Fourier space, with the environment-induced modification of the optical emission rate (Purcell effect). The emissive power inside and outside are calculated for corrugated OLEDs. We find it exhibits high light outcoupling 60~65% for optimal pitch values between 1-2.5 microns.