The room temperature luminescence spectra of the monoterpyridyl chelates of trivalent samarium, dysprosium and thulium have been studied in solid state by exciting with monochromatic radiation of 3200 Å. The spectra of these chelates show intra f → f fluorescent transitions of the chelated rare earth ions as well as the molecular band fluorescence. The “bottleneck” nature of the energy transfer from the nitrogen containing heterocyclic ligands to the coordinated rare earth ions is proposed. The fluorescence data of mono-terpyridyl chelates have been compared with those of bis-dipyridyl one. The phosphorescence spectrum of terpyridyl has also been investigated. The lowest triplet state of the free ligand is found at 22 940 cm-1 above the ground level. The phosphorescence lifetime of terpyridyl is about 2 sec