The performance of electrochemical biosensors developed for the determination of inhibiting species is considered. The role of various factors affecting the analytical characteristics of biosensors, their selectivity toward inhibitors to be tested as well as operational characteristics is discussed. The choice of enzyme-inhibitor system, the influence of enzyme immobilization on the behaviour of a biosensor, the modes of the optimization of working conditions are discussed. Most conclusions are illustrated with the models of the application of biosensors for monitoring environmental pollutants.