Background:The Extended spectrum β-lactamases (ESBLs) production is one of the most essential mechanism of drug resistance in Proteus mirabilis (P. mirabilis). Objective: Phenotypic and genotypic detection of extended spectrum β -lactamases production in P. mirabilis and its antimicrobial resistance among clinical isolates. Methods: A total of Sixty P. mirabilis clinical isolates were tested for Extended spectrum β lactamase production by modified double disc synergy test (MDDST). Polymerase chain reaction (PCR) was done to detect Extended spectrum β-lactamases genes in the clinical isolates. Antimicrobial susceptibility testing was done by means of Kirby Bauer disc diffusion method. Results: Out of the 60 P. mirabilis clinical isolates, 17 isolates (28.33%) were ESBL producers by phenotypic test. Genotypically; ESBLs genes were detected and the most prevalent ESBL resistance gene was TEM (91.7%) followed by SHV (75%), CTX-2-59 (56.7%) and CtxM-15 (51.7%). Moderate level of resistance to ofloxacin, ciprofloxacin, amoxicillin/ clavulanic acid, cefotaxime and ceftazidime (60.0%, 58.3%, 45.0%, 41.7% and 40.0% respectively) was recorded. In addition, 73.33% of isolates were classified as multidrug resistant (MDR). Conclusion: Monitoring of Extended spectrum β-lactamase producing P. mirabilis is very important because of its high prevalence among urinary tract infections. Also; increasing awareness for clinicians and enhancing laboratories tests leading to reduce the spread of these isolates.