Aliphatic hydroxamic acids (AHAs) at C2, C6, C8, C10, C12, C17 and their metal complexes (Fe(II), Fe(III), Cu(II), Zn(II) and Ni(II)) have been synthesized. The compounds have been characterized by ¹H- and ¹³C-NMR, and infrared spectroscopy, and the complexes have been further studied by UV spectroscopy, mass spectrometry, Karl Fischer titration, cyclic voltammetry and X-ray diffraction. The biological activity of the compounds has been evaluated using various microorganism, including bacteria (3 Gram-positive and 3 Gram-negative), 1 strain of mycobacteria and 2 strains of fungi by microdilution method. Regarding AHAs, HA12 displayed the best minimum inhibitory concentration (MIC) for several microbial strains in the study. The zinc complexes, as well as ZnCl₂ itself, showed a lower MIC than their iron counterparts on E. coli . Copper, zinc and nickel complexes of HA12 have showed a very interesting antifungal effect on C. albicans. Finally, the toxicity of compounds with significant antibacterial and antifungal activity has been assessed on cervical cancer cells. These results need further studies to assess the potential interest of these compounds in medicine.