The FT-infrared (400-4000 cm(-1)) and FT-Raman (100-3500 cm(-1)) spectra of N-aminophthalimide and 3-aminophthalhydrazide were recorded. The observed frequencies were assigned to various modes of vibrations on the basis of normal coordinate analysis, assuming C-S point group symmetry. The potential energy distribution associated with normal modes is also reported. The assignments of fundamental vibrations agree well with the calculated frequencies.