The current research conducted a comprehensive analysis of the thermal and biological properties of novel Ni(II) complexes of pyrazolone. To synthesize these compounds, various 4-acyl pyrazolones were utilized, and the resulting ligands were characterized using 1H NMR, IR, 13C NMR, elemental analysis, and UV spectroscopy. Additionally, the complexes were characterized using elemental analysis, UV spectroscopy, IR spectroscopy, and thermal analysis techniques such as TGA/DTG and DSC. To assess their potential, all the compounds underwent antibacterial and antimalarial testing. The findings revealed significant promise, warranting further investigation in this field.