Thirty two new Cu(II), Ni(II) and Zn(II) complexes (1-32) with salicylidene thiosemicarbazones (H₂L¹-H₂L¹⁰) were synthesized. Salicylidene thiosemicarbazones, of general formula (X)N-NH-C(S)-NH(Y), were prepared through the condensation reaction of 2-hydroxybenzaldehyde and its derivatives (X) with thiosemicarbazide or 4-phenylthiosemicarbazide (Y = H, C₆H₅). The characterization of the new formed compounds was done by ¹H-NMR, ¹³C-NMR, IR spectroscopy, elemental analysis, magnetochemical, thermoanalytical and molar conductance measurements. In addition, the structure of the complex 5 has been determined by X-ray diffraction method. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60) cells growth and antibacterial and antifungal activities.