Background: Klebsiella pneumoniae (K. pneumoniae) is a common pathogen involved in a diverse array of life-threatening infections. Increasing frequent acquisition of antibiotic resistance by K. pneumoniae has given rise to multidrug-resistant pathogen mostly at the hospital level. Objectives: To assess the prevalence and antibiotic resistance pattern of the clinical K. pneumoniae isolates at Menoufia University Hospitals (MUHs) as well as to explore the role of mrkD gene as a regulator of biofilm formation. Methodology: A total of 340 different clinical samples were obtained from 270 patients who were admitted to MUHs and those from Outpatient clinics during the period from April 2018 to September 2019. 84 K. pneumoniae isolates were identified by the standard microbiological methods and vitek-2 system. The antimicrobial resistance pattern was determined by disk diffusion method. The biofilm-forming ability of all K. pneumoniae isolates was demonstrated phenotypically by the modified Congo red agar method (MCRA) and PCR assay verified the presence of mrkD gene as a genetic determinant of biofilm formation. Results: Klebsiella spp. represented 34.7% of the collected isolates and the predominant spp. was K. pneumoniae (91.3%). The highest resistance rates were for ceftriaxone (69%) followed by aztreonam (67.9%), 66.7% for each of piperacillin and ceftazidime, while the least resistance rate was for fosfomycin (8.3%). Biofilm production was detected among 83.3% of the isolates by MCRA method. A highly significant statistical difference was noted between biofilm- and non- biofilm -producing K. pneumoniae isolates regarding resistance to cefepieme and amikacin (P <0.001) and similarly regarding resistance to aztreonam, imipenem, meropenem, ertapenem and tobramycin (P<0.05). Conventional PCR assay showed that, 92% of the isolates harbored mrkD gene with a highly significant association with biofilm formation. Conclusion: The increasing prevalence and remarkable ability to acquire antibiotic resistance among K. pneumoniae isolates together with biofilm formation should alert even more regarding the hazard of this pathogen in hospital settings.