For the modern smart lighting systems one of the most attractive LED advantages is the dimming possibility. Many researchers and engineers from the field of lighting engineering are trying to find compromise between the efficiency of LED dimming process and the ease of its implementation. This paper also presents an attempt to improve LED dimmer parameters. Comparative investigation of the operation of buck LED drivers in continuous conduction mode and discontinuous conduction mode are discussed here. The first section of paper briefly describes the controllability parameters of the converter in both of these modes. The positive impact of discontinuous conduction mode on the controllability parameters as well as the results of the analytical estimation and the results of associated experiments are summarized at the end of the first section. The second section describes the impact of discontinuous conduction mode on the losses of LED dimmer. The analytical estimation of power losses in the main converter components for both operation modes as well as the summary of the experiments to identify distribution of power losses between these components are presented in this section. Finally, the conclusions about using discontinuous conduction mode for dimmable LED lamps as well as guidelines for the choosing of the components with the most appropriate parameters are drawn.