Context: Joint complaints in patients with acromegaly are common, although the long-term disease course is largely unknown. Objective: This study aims to evaluate the long-term course of acromegalic arthropathy. Design and Setting: A prospective longitudinal cohort study was conducted in controlled acromegaly patients followed at a tertial referral center, with 3 study visits: at baseline and after a median of 2.6 and 9.1 years. Patients: We included 31 patients with biochemically controlled acromegaly for 2 or more years (49% female; median age, 60 years) at baseline. Main Outcome Measures: Radiographic arthropathy of the knee, hip, hand, and cervical and lumbar spine were evaluated using Kellgren and Lawrence (KL) scores, developed for assessment of primary osteoarthritis (OA). Radiographic progression was defined as a KL increase above the smallest detectable change. Joint symptoms were assessed using self-reported questionnaires. Progression was defined using existing clinically important cutoff values. Risk factors for progression were investigated using a multivariable model. Results: All patients had definite radiographic OA at 1 or more joints at baseline. Radiographic progression was observed in 29%, 48%, 84%, and 94% of patients in the knees, hips, hands, and axial joints, respectively. Deterioration in hand-related pain and function was observed in 10 (32.3%) and 11 patients (35.5%), respectively. Solely baseline KL scores of the hip were associated with hip OA progression (OR 1.88; 95% CI, 1.09-3.16). Conclusions: Acromegalic arthropathy showed significant radiographic progression over 9.1 years of follow-up in patients in remission, whereas clinical progression was observed less frequently. Future studies should focus on adequate prevention and treatment strategies of acromegalic arthropathy.