We report the synthesis of a series of conjugated zinc porphyrin oligomers designed as photodynamic therapy agents. These compounds exhibit exceptionally high two-photon absorption cross-sections, redshifted linear absorption spectra, and high singlet oxygen quantum yields, making them ideal for one-photon- and two-photon-excited photodynamic therapy. These products are substituted by three α-mannose units on each chromophore with the aim to target tumor cells with over-expressing lectin-type membrane receptors.