The study's objective was to determine Proteus mirabilis susceptibility in individuals with urinary tract infections and stones to antibiotics and prescribe optimal antimicrobial treatment. Nonrepetitive Proteus mirabilis strains were isolated from urine specimens obtained from 317 patients diagnosed with urinary stones from January, 2018, to December, 2021. A VITEK mass spectrometer was used for species identification, and a VITEK-compact 2 automatic microbial system was used for the antimicrobial susceptibility test (AST). Susceptibility to imipenem and cefoperazone/sodium sulbactam was tested by the disc diffusion method (K-B method). The antibiotic sensitivity of the strains was analyzed by sex and season. A total of 317 patients were reviewed: 202 females (63.7%) and 115 males (36.3%). Proteus mirabilis infections were observed during spring (21.8%, n = 69), summer (26.2%, n = 83), autumn (33.8%, n = 107), and winter (18.2%, n = 57). Proteus mirabilis infections in females were diagnosed most often during the fall (24.3%, n = 77) and during the summer in males (11.0%, n = 35) (p = 0.010). Female patients responded best to levofloxacin (p = 0.014), and male patients responded best to sulfamethoxazole (p = 0.023). Seasonal variation in antibiotic sensitivity was confirmed, with significantly higher rates in the winter for cefuroxime (p = 0.002) and sulfamethoxazole (p = 0.002). Significant seasonal increases were also found in levofloxacin sensitivity during the summer (p = 0.005). Highly effective antibiotics such as cefoxitin and ceftazidime should be used empirically by considering antibiotic sensitivity changes by sex, season, and year. Regional studies should be conducted frequently.