Schiff base complexes of dysprosium derived from alpha napthyl amine with different aldehydes viz.4 methoxy benzaldehyde, 4 hydroxy benzaldehyde. Schiff bases were prepared by condensation alpha napthyl amine with different aldehydes. The prepared Schiff bases and their dysprosium complexes have been characterized by elemental analysis, IR,¹H NMR spectral studies. The ligands and their dysprosium complexes have been screened for their biological activity against the bacteria, S. aureus, E.coli and the fungi Penicillium crysogenum and Aspergillus Niger. The Schiff bases and their dysprosium complexes show variable activity of inhibition on the growth of bacteria and fungi.