Introduction: Low back pain (LBP) is a widespread musculoskeletal disorder affecting millions globally, contributing significantly to disability, reduced productivity, and impaired quality of life. It is a leading cause of disability, impacting both developed and developing nations worldwide. Objective: The aim of this study was to investigate the etiological status and treatment outcomes of LBP among patients treated under the orthopedic department of a tertiary level hospital in Bangladesh. Methods: This prospective observational cross-sectional study was conducted jointly at the Department of Orthopedics in Bangladesh Central Police Hospital (CPH), Dhaka, Bangladesh and at the department of Physical Medicine, Shahabuddin Medical College Hospital, Dhaka, Bangladesh, during July 2024 to December 2024. Consecutive sampling method was applied, and a total of 300 patients aged ≥15, presenting with low back pain (LBP) at the outpatient department (OPD) were enrolled in this study. The collected data were methodically organized and analyzed using Statistically Package for Social Sciences (SPSS), Version-23.0. Results: A total of 300 patients presenting with low back pain (LBP) were enrolled in this study. The mean age of the patients was 46.9 ± 2.57 years. The most common age group was 41-50 years, comprising 70 (37.6%) patients. The majority of the patients were females (109, 58.6%). Hypertension (HTN) was the most prevalent comorbidity, present in 84 (45.2%) patients. Among the patients with mechanical pain, spondylosis was the most frequent cause, observed in 130 (43.33%) patients, which included acute pain in 65 (50%), sub-acute in 20 (15.38%), and chronic in 45 (34.61%). Disc prolapse accounted for 122 (40.67%) patients, with 56 (45.90%) acute, 18 (14.75%) sub-acute, and 48 (39.34%) chronic presentations. Other notable mechanical causes included back strain109 (36.33%), spondylolisthesis 80(26.67%), sacroiliac joint sprain 29 (9.67%), and spinal stenosis 22(7.33%).