Electrical conductivities of CoBr2 and CoBr2 (1) + KBr (2) mixtures in the whole range of compositions were measured as a function of the temperature by the conductometric method. Parameters of an Arrhenius-type equation, preexponential factors and activation energies for conduction of molten salts, calculated with the least-squares method are given. The electrical conductivity of the molten CoBr2, reported here for the first time, shows a high value of activation energy of (30.90 +/- 0.52) kJ(.)mol(-1), decreasing on addition of KBr, probably due to disruption of a network structure of the pure molten cobalt dibromide. Comparing the conductivity isotherms at 1100 K for the molten systems CoCl2 (1) + KCl (2) and CoBr2 (1) + KBr (2), one notes that that of the CoCl2 ( 1) + KCl (2) system is rather regular, whereas in the CoBr2 (1) + KBr (2) system a significant drop of conductivity is observed at x(1) = 0.333. This last may indicate the formation of the complex ions CoBr42- in the liquid mixture in the course of melting of the compound K2CoBr4.