Liquid flow analytical techniques are classified, and definitions are provided of flow-injection analysis, segmented flow analysis, flow titration, continuous monitoring, liquid chromatography, and capillary electrophoresis. Electrochemical detection and flow through detection cells are characterized with respect to the surface and bulk detection. The detector performance is discussed in terms of its principal analytical parameters, such as detection limit and dynamic concentration range, as well as its dynamic characteristics, such as the response time, sampling frequency, transport lag, and long-term stability. Moreover, different detection modes are critically evaluated, including both potentiostatic and galvano-static techniques. Factors influencing sensitivity and detection limit, which include electronic and hydrodynamic approach, are also discussed. Different detector designs are critically reviewed, and the special features of electrochemical detectors for flow analytical techniques are emphasized.