Fast cyclic voltammetry (FCV) differs from all other voltammetric methods in the type of waveform used, the speed of measurement and the applications for which it is best suited. The main assets of FCV are its high spatial and temporal resolution, the use of a reduction scan and the ease with which it can be combined with unit activity recording at the same electrode. The drawbacks of the method are the inability to measure basal extracellular amine levels or changes in multicomponent signals, and the modest sensitivity of the technique. Principal applications of FCV are the monitoring of ionophoresed or pressure-ejected monoamines, direct measurement of stimulated amine release and uptake, and the study of brain ascorbic acid function. The high spatial (5 microns) resolution of FCV is such that the anatomical heterogeneity of brain nuclei can be measured in great detail. The temporal resolution (25 ms) means that transmitter release and uptake can be measured essentially in 'real time'.