Biologically active La (III), Sm (III) , Gd (III) and Dy (III) complexes were synthesized by using Furan-2- carboxylic acid (FCA) as ligand and were characterized by elemental analysis and spectral measurements. Coordination of the ligand atoms to the metal ion was deducted by IR spectral data. The in vitro antibacterial screening of the free acid and its metal complexes has been carried out against Pseudomonas and bacillus. Antifungal activities of all the synthesized compounds were screened for in vitro growth inhibitory activity against Aspergillus flavus and Aspergillus niger , Aspergillus fumigatus by using the cup plate method. Antimicrobial activities of the ligand increase on coordination with the metal ion and show more promising activity than the corresponding free acid, and the standard control antibiotics. Such increased activity of the metal chelates can be explained on the basis of Overtone’s concept and chelation theory.