Chloride reacts with benzimidazole (BzlH) in the molar ratio 1:2 or 1:3 in ethanol at room temperature to produce CoCl2L2 (L = BzlH) and Co(L-H)2 (L-H = Bzl) As dark blue and purple solids respectively. The former complex is soluble in ethanol or acetone whereas the latter is insoluble in these solvents. The above reaction under refluxing condition yields exclusively Co(L-H)2. Neutral or basic condition seems to favor the reaction as acidic medium does not give any complex. Co(L-H)2 reacts with acetic acid to form Co(CH3COO)2L2 as pink crystals and this complex can also be obtained by reacting cobalt acetate with stoichiometric quantities of BzlH in ethanol at RT, and the latter at refluxing temperatureproduces Co(L-H)2. The complexes have been further characterized by elemental analysis,IR, UV-Visible spectroscopy, conductivity and magnetic susceptibility measurements. CoCl2L2 and Co(CH3COO)2L2 complexes are mononuclear and are proposed to have tetrahedral and octahedral structure respectively. Co(L-H)2 is polymeric with bridging benzimidazole (BzlH) and is assigned a tetrahedral geometry around each metal ion.