Analytical applications of electrogenerated chemiluminescence (ECL) are reviewed with emphasis on the years 1997-2000. Recent developments are described for the ECL of organics, metal complexes and clusters, cathodic ECL on oxide covered electrodes, ECL based immunosensors, DNA-probe assays and enzymatic biosensors. Mechanisms are given for polyaromatic hydrocarbons, luminol/hydrogen peroxide, some cathodic ECL reactions and ruthenium complexes with and without co-reactants. New developments and improvements of techniques and instrumentation and their application to analytes are described. The application of ECL for visualisation of electrochemical processes and imaging of surfaces is mentioned.