Ciaftalan Zinc (also known as Zinc(II)-phthalocyanine) is phthalocyanine and photosensitizers which showed a high activity in photodynamic therapy studies on a variety of animal tumors. Ciaftalan Zinc belongs to second generation photosensitizers that have a more intense long wavelength absorption and greater extinction coefficient compare to the first generation. The greater the extinction coefficient value associated with greater efficacy, smaller drug dosage required to induce a cytotoxic response and diminished risk of provoking systemic toxic reactions. The long absorption wavelength correlates with higher penetration depth and it is, therefore, Ciaftalan Zinc causes deep tumor necrosis in animal models. Currently, Tetra-triethyleneoxysulfonyl substituted Ciaftalan Zinc derivatives are studied as novel photodynamic therapy of cancer.