Otopathogens such as Moraxella Catarrhalis and Haemophilus influenzae are the major causes of pediatric chronic and recurrent otitis media (OM). This pilot study showed that both M. catarrhalis and H. influenzae were highly susceptible to antimicrobial blue light (aBL) inactivation at 405 nm, either in suspensions and biofilms. Transmission electron microscopy showed aBL-induced damage of cell membrane in M. catarrhalis cells. Ultra-performance liquid chromatography results revealed that protoporphyrin IX and coproporphyrin are the most abundant species of endogenous porphyrins in M. catarrhalis. Our findings suggest that aBL is potentially an effective alternative antimicrobial therapy for OM.