If rapid quantitative electrochemical analysis was to evolve, the charging current that plagues electrochemical measurements had to be minimized. These currents occur when rapidly changing potentials are applied to an electrode solution interface. This initated the research of modified potential waveforms such as those used in pulse and square wave polarography. These methods have been shown to filter out much of the effect of charging current and are used extensively in routine analysis. Similarly, pulse methods coupled with cyclic voltammetry also reduce noise and analysis times and in addition provide more qualitative information. A historical review of the various techniques that reject charging current is discussed with emphasis placed on recent studies with modified cyclic voltammetry waveforms.