Abstract Disclosure: F. El Sayed: None. Background Paget disease of bone is an age-related disorder characterized by abnormal growth in certain bones, leading to changes in size and shape. Commonly affecting the skull, spine, pelvis, and long bones, it is more prevalent in men, those over 55, with a family history, and of European ancestry. The prevalence of Paget's disease of bone is approximately 2-3% in individuals over 55 in the United States and Europe, with higher rates in those of European descent. Symptoms, such as pain and deformities, may arise from the condition itself or complications like arthritis. While Paget disease can cause visible abnormalities and fractures in affected bones, most individuals remain asymptomatic. Diagnosis often involves blood tests measuring alkaline phosphatase levels, bone scans, and x-rays. Case Presentation We present the case of a 34-year-old woman who sought evaluation due to persistently elevated alkaline phosphatase (ALP) levels in the thousands. The abnormality was discovered during routine blood work conducted during her pregnancy in 2020, and subsequent investigation revealed a chronic elevation for over three years. The patient reported chronic lower back pain but denied other neurological symptoms. Quantification of ALP Bone showed elevated levels at 629, with normal aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, as well as within-range calcium and gamma-glutamyl transferase (GGT). A whole-body bone scan revealed marked radio tracer uptake in the calvarium, raising concerns for Paget's disease. The patient received a one-time infusion of Zoledronic acid (5 mg), leading to a significant decrease in ALP levels to 182 after three months. Subsequent examination by an Ear, Nose, and Throat (ENT) specialist unveiled bilateral extra bone deposition and mild hearing loss in the right ear, adding a unique dimension to the patient's presentation. This case highlights the importance of a comprehensive approach to diagnose and manage Paget's disease, even in younger individuals with atypical symptoms. Discussion and conclusion Paget's disease presenting in young adults with back pain can be a diagnostic challenge due to its atypical occurrence in this age group. Although back pain is a common symptom, the underlying cause might not immediately be linked to Paget's disease, which typically affects older individuals. However, when encountering persistent back pain in young adults, especially when accompanied by elevated alkaline phosphatase levels, clinicians should consider Paget's disease as a potential differential diagnosis. Further investigation, including imaging studies and bone scans, becomes crucial to confirm the presence of Paget's disease and initiate appropriate management strategies to mitigate its impact on the patient's health and quality of life. Presentation: 6/2/2024