Pseudomonas aeruginosa is an opportunistic gram‐negative human pathogen that causes a wide range of infections, including nosocomial infections. Aside from the intrinsic and acquired antimicrobial resistance against many classes of antibiotics, P. aeruginosa can produce an extracellu‐ lar polymeric matrix called “biofilm” that protects bacteria from antibiotics and harmful factors. Biofilm enables P. aeruginosa to develop chronic infections. This study assessed the inhibitory action of ZnO‐nanoparticles against biofilms formed by multidrug‐resistant P. aeruginosa strains. A collec‐ tion of 24 clinical strains of P. aeruginosa were tested for their antimicrobial resistance against differ‐ ent antibiotics using the disk diffusion method. The antibiofilm activity of ZnO‐NPs was assessed using the microtiter plate biofilm assay. The application of ZnO‐NPs dramatically modulated the resistance profile and biofilm activity of P. aeruginosa. The combination of ZnO‐NPs and mero‐ penem showed synergistic antipseudomonal activity with lower MICs. The scanning electron mi‐ croscope (SEM) micrographs revealed complete inhibition of biofilms treated with the meropenem– ZnO‐NPs combination. Reduced expression of biofilm regulating genes lasR, pslA, and fliC was de‐ tected, reflecting the enhanced antibiofilm effect of ZnO‐NPs. In vivo application of this antimicro‐ bial mixture completely cured P. aeruginosa‐induced keratitis in rats. Our findings represent a dual enhancement of antibacterial and antibiofilm activity via the use of meropenem–ZnO‐NPs combi‐ nation against carbapenem‐resistant P. aeruginosa infections