Fluoro-substituted zinc(II)phthalocyanines (RS) 4 ZnPcs were prepared. All the structures of newly synthesized compounds was evaluated by IR and 1 H NMR spectral analysis. They were tested against human adenocarcinoma prostate cancer cells. A type II membrane antigen highly expressed in prostate cancer, namely prostate-specific membrane antigen, has been an attractive target for imaging and therapy. To investigate the structureactivity relationships of (RS) 4 ZnPcs 4a-c in human adenocarcinoma prostate cancer cell model, 3 fluoro-substituted zinc(II)phthalocyanines with different terminal heteroaromatic rings have been designed and evaluated for their antiproliferative potency in vitro. The detailed LD50 values of the targeted compounds were reported. Our preliminary in vitro studies confirm that (RS) 4 ZnPcs 4a-c could act as an attractive photosensitizer for the early diagnosis of prostate cancer.