A dynamic characterization procedure and a mathematical modeling of OLEDs are proposed in this paper. Four OLED commercial devices are characterized and from this, a mathematical modeling is performed based on a theoretical equivalent model. The objective is to understand the OLED operation and to predict theoretically their electric and photometric dynamic behavior. The target is to provide useful guidelines for an adequate OLED driver design. In order to validate the theoretical approach, the OLED samples are experimentally tested under different operating frequencies. The comparison among theoretical, simulation and experimental results, demonstrates acceptable accuracy.