Introduction: Otitis Externa is one of the most common diseases that physicians deal with. The purpose of this study was to find out the prevalence of microbial agents and pattern of antimicrobial resistance in patients with acute otitis externa in the desert region of Rafsanjan.   Material and methods: After examination and diagnosis of acute Otitis externa, a sterile swab sample was taken from the ear. The culture was then performed on the Triptic soy broth environment. If the microbial culture was positive, antibiogram was performed according to NCCL standard.   Results: Out of 124 patients with Otitis Externa, 88 showed positive culture and 36 had negative culture. The most common microorganism isolated was Staphylococcus aureus (29%) followed by Pseudomonas aeruginosa (25.8%). In 12 cases (11.88%), fungi was found alone and in nine cases (7.24%) fungi and bacteria were found together. In 14 cases (11.29%) out of the 124 cases, there were two or more bacteria in microbial cultures. The most sensitive of antibiotics were ciprofloxacin and vancomycin and the most resistant type of antibiotics were cotrimoxazole and cephalexin.   Conclusions: In this study, the effects of weather and climate variability on antimicrobial agents were observed in Otitis Externa. It is recommended that before the start of the treatment, laboratory investigations be performed to identify the causative agents.