Our goal was to deduce the prevalence of low back pain among medical doctors in the teaching hospitals of Karachi, Pakistan, along with its associated variables and the functional disability accompanying it. This cross-sectional study was conducted among medical doctors from Creek General Hospital and United Hospital, affiliated with United Medical and Dental College, Karachi, Pakistan. A sample of 80 participants was included in this study, and a non-probability convenient sampling with randomization was utilized. Using a three-part questionnaire that included the Oswestry Disability Index, all participants were scrutinized for low back pain with its characteristics, associated risk factors, and functional disability. Seventy percent of medical doctors included in this study suffered from the problem of low back pain, with 68% experiencing it over the last 3 months to 1 year. Furthermore, 89% and 11% suffered from minimal and moderate disability, respectively, affecting day-to-day and work life. Moreover, this study also found a significantly positive association (p value < 0.05*) of low back pain with age and work-related characteristics and was more common in those with work experience between 1 and 10 years, >8 working hours, >4 standing hours, and belonging to the surgery and medicine specialties. The association was significantly positive according to the chi-square/Fischer exact test. Our study addressed the evidence that low back pain is prevalent among medical doctors in teaching hospitals in Karachi, Pakistan, potentially affecting patient treatment and student education and accentuating the need for further intervention and research among doctors worldwide.