Thiosemicarbazide derivatives are widely used in medical practice as antimicrobial, antituberculous, antifungal, antitumor and other kind of preparations. Their biological activity in many cases is determined by the possibility of formation of different coordination compounds with biometal ions in the living organism. Therefore, accumulation and systematization of the experimental data on synthesis and properties of new coordination compounds of biometals with thiosemicarbazide derivatives remains an actual direction of the modern chemistry. The aim of this work is the determination of bacteriostatic and bactericidal activities of cobalt, nickel, and copper coordination compounds of salicylidene-4-(2-(H2L1), 3-(H2L2), 4-(H2L3)-methoxyphenyl)thiosemicarbazides. The salts of stated above biometals react with azomethines H2L1–3 forming coordination compounds with composition Cu(HL1–3)X (X=Cl-, NO3-), CuL1–3·H2O, Co(L1,3)2Cl, Ni(HL1–3)2, NiL1–3·H2O. The antimicrobial activity of these compounds was studied in vitro using the method of two-fold serial dilutions in liquid nutrient medium (meat infusion broth, pH = 7.0). The substances were dissolved in DMSO in concentration of 10 mg/mL. The next dilutions were made using meat infusion broth. The antimicrobial activity was tested using standard strains of gram-positive (Staphylococcus aureus ATCC 25923), gram-negative (Escherihia coli ATCC 25922, Klebsiella pneumoniae) bacteria and Candida albicans fungus. It was established that the synthesized substances show selective bacteriostatic and bactericidal activities towards studied strains of microorganisms in the range of concentrations 2–500 μg/mL. The thiosemicarbazone H2L2 and its biometal coordination compounds show the highest antimicrobial activity. The coordination compounds that contain H2L1 in their composition are the most active towards Staphylococus aureus. Staphylococcus aureus and Candida albicans are the most sensitive strains to the studied series of substances. The position of methoxy radical in the azomethine has an influence on biological activity of the corresponding thiosemicarbazone and its biometal coordination compounds. In most cases meta-isomer and coordination compounds of this thiosemicarbazone show the highest antimicrobial and antifungal activities. The nature of acid residue practically doesn’t affect the biological activity of the synthesized substances. The determinated properties of the synthesized substances are of interest for medical practice for enhancement of the arsenal of antimicrobial and antifungal preparations that are active to the resistant forms of microorganisms and fungi.