The metallothionein (MT) family is a class of low molecular weight, intracellular and cysteine-rich proteins presenting high affinity for metal ions. MTs are involved in many pathophysiological processes such as metal ion homeostasis and detoxification, protection against oxidative damage, cell proliferation and apoptosis, chemoresistance and radiotherapy resistance. The MT overexpression is statistical significant at malignant and high grading tumours. Therefore it is necessary to suggest new methods for determination of MT. Electrochemical techniques enables to perform highly sensitive, low cost and easy-to-use determination of many biological active compounds. Here we studied the electrochemical behaviour of metallothionein by both stationary and flow system with electrochemical detection. The stationary electrochemical measurements (square wave voltammetry - SWV) were performed with the AUTOLAB Analyser using a standard cell with three electrodes, where the glassy carbon electrode served as a working electrode. Flow injection analysis with electrochemical detection (FIA-ED) was consisted from a chromatographic pump, a reaction coil and an electrochemical detector (Coulochem III) with glassy carbon electrode as a working electrode. Metallothionein gave signal at potential of 0.8 V using SWV. The SWV detection limit of MT was about units of micrograms per millilitre. In addition we performed the MT analysis using of FIA-ED. It was evident from the hydrodynamic voltammogram that the highest MT signal was obtained at detector potential of 0.8 V. In addition we studied relationship between overexpression of MT and progression of diseases in human tumours. MT overexpression would be a new prognostic marker of progression of tumours disease.