In the present work, a green emitting composite with attractive photoluminescent properties was obtained through the embedding of the Tb3+ complex with N-hydroxyphthalimide in a poly-(N-vinyl-pyrrolidone) matrix, which was further processed in thin or thick films. First, several complexes of Gd3+, Tb3+, and Y3+ with N-hydroxyphthalimide with the general formula [M(NHF)(3)(DMF)(2)] were prepared at a 1:3 metal/ligand ratio. The Tb3+ complex presents specific emission peaks, with the most intense peak located at 543 nm, thus being selected for incorporation in the poly(N-vinyl-pyrrolidone) matrix. The prepared complexes and composites were investigated through elemental analysis, thermal analysis, FT-IR, P-XRD, and SEM. The photoluminescent properties were studied in detail. Remarkably, through the embedding in the poly(vinyl-pyrrolidone) matrix, the photoluminescent properties of the Tb3+ complex are notably enhanced compared to the free complex.