New porphyrin/4-oxoquinoline conjugates were synthesized from the Heck coupling reaction of a β-brominated porphyrin with 1-allyl-4-oxoquinoline derivatives, followed by demetallation and deprotection affording the promising photosensitizers 9a–e. Singlet oxygen studies have demonstrated that all the porphyrin/4-oxoquinoline conjugates 9a–e were capable of producing cytotoxic species and found to be excellent photosensitizing agents in the inactivation of S. aureus by the antimicrobial photodynamic therapy (aPDT) protocol.