This study aims to prepare (99m)Technetium Pheophorbide-a (Tc-99m-PH-A) complex and evaluate its efficiency as an infection imaging agent. First, PH-A was obtained from Spirulina maxima algae, and the product compound was confirmed using H-1 NMR and MS (ESI) methods. The PH-A was then labeled with Tc-99m using the tin chloride method and its biological efficacy as a potential radiotracer for Staphylococcus aureus (S. aureus) infection was evaluated in bacterially infected and sterile inflamed rats. The radiochemical stability of the Tc-99m-PH-A in human serum was determined by thin-layer radiochromatography (TLRC). The radiochemical purity was 87 +/- 3.2% and remained constant at more than 80 +/- 0.1% even in serum for 120 min after radiolabeling.