The synthesis and characterization of axially bis(1,2,26,6-pentamethy1-4-piperidinol) silicon(IV) phthalocyanine (3) and its water-soluble cationic derivative (3Q) were defined in this study. Both newly synthesized silicon(IV) phthalocyanines were characterized by FT-IR, UV-Vis, H-1 NMR, MALDI-TOF and elemental analysis as well. Although the photo-physical and photochemical properties of newly synthesized axially bis(1,2,2,6,6-pentamethyl-4-piperidinol) silicon(IV) phthalocyanine was investigated in DMSO, its water-soluble derivative was investigated in both DMSO and phosphate buffer saline (PBS). The fluorescence quenching behavior of the studied water-soluble silicon(IV) phthalocyanine (3Q) by the addition of 1,4-benzoquinone (BO) was also described in DMSO. Besides, the binding behavior of 3Q, it was examined by bovine serum albumin (BSA) protein in PBS for determination of transportation abilities of this phthalocyanine in the blood Photodynamic activity of water-soluble silicon(IV) phthalocyanine (3Q) was tested in vitro on tumor cells and for inactivation of bacterial pathogens with promising photocytotoxicity for both PDT applications.