The research team has previously reported the synthesis of a new type of stable 4,5,6,7-tetrahydropyrazolo[1,5-a] pyridine-fused chlorins and bacteriochlorins via an [8π+2π] cycloaddition of diazafulveniummethides with porphyrins and chlorins. Absorption spectra of these chlorins and bacteriochlorins revealed intense absorption bands within the therapeutic spectral window, at 650 nm and 730 nm, respectively. Preliminary studies on phototoxicity of some of the compounds in melanoma cells proved this class of compounds to be very active as photodynamic agents against melanocytic melanoma (A375) and amelanotic melanoma (C32) cells. Interestingly, a di(hydroxymethyl)chlorin derivative was particularly active against human melanocytic melanoma cells (IC50 = 31 nM). Near infrared (NIR) luminescent compounds based on platinum(II) derivatives of 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused chlorins have also been prepared which proved to be very promising theranostic cancer agents. Further studies have been carried out demonstrating the high potential of these Macrocycles in photodynamic therapy of several cancers. In this lecture, further details of this study will be presented and discussed.