New heterocyclic derivatives of 8-hydroxyquinoline were prepared and screened as antimicrobial agents. Chemical structures were elucidated and confirmed using different spectroscopic methods such as elemental analysis data, Infrared, Nuclear Magnetic Resonance Spectroscopy. In order to explore their potential biological activity, the “in vitro” antibacterial activity was investigated against [E. coli (ATCC35218), S. aureus (ATCC29213), V. parahaemolyticus (ATCC17802), and P. aeruginosa (ATCC27853)]. The studied compounds exhibited a remarkable antibacterial activity superior to the standard antibiotic (Penicillin G). These new heterocyclic derivatives of 8-hydroxyquinoline, which proved to be potentially effective, can be used as alternative chemical antimicrobial agents applications. It was very interesting to observe that POM (Petra/Osiris/Molinspiration) bioinformatic analyses of the 8-hydroxyquinoline derivative (5) exhibited more important antibacterial activity (MIC = 10−6 mg/mL against V.p and S.a bacteria) and good drug score (DS = 0.71) when compared with Penicillin (DS = 0.33; MIC = 10−3 mg/mL).