In this work, the complexation reaction between La(III) ion and gatifloxacin drug belongs to flouroquinolone family was studied in an ethanolic solution. The coordination behavior of the formed complex was investigated by different techniques. The elemental analysis shows that the metal to ligand ratio of 1:1. The molar conductance measurement display the none electrolytic nature of the complex. The thermal behavior of the complex was investigated and the thermal decomposition pathways have been postulated showing that the final product is metal oxide and eight carbon atoms. Antibacterial and antifungal properties of the metal complex has also been examined against Gram positie bacteria (Bacillus Subtilis, and Staphylococcus aureus) and Gram negative bacteria (klebsiella pneumoniae, and Escherichia coli in addition to fungai (Candida albicans, Candida tropicalis, Aspergillus flavus, and Fusarium oxysporum). Gatifloxacin drug and its complex were found to be have variable degree of a remarkable biological activity.