The purpose of this study was to examine the relationship between patient age, acromial morphology, and rotator cuff pathology. Data on 523 patients who had arthroscopic and/or open shoulder surgery were reviewed. Acromial morphology was classified by the system of Bigliani. All patients were categorized by postoperative diagnosis as having tendinitis of the rotator cuff, partial rotator cuff tear, complete rotator cuff tear, and non-rotator cuff-related pathology. Univariate analysis results for acromial morphology (P <.001), age (P <.001), and gender (P =.019) showed a significant association with rotator cuff pathology. Fifty percent of patients with rotator cuff tendinitis had type I acromions, and 58% of patients with full-thickness rotator cuff tears had type III acromions. Stratified univariate analysis revealed no significant association between acromial morphology and rotator cuff pathology in patients who were over 50 years old. Patients with full-thickness rotator cuff tears were significantly older than those with partial-thickness tears or tendinitis. A larger proportion of male patients than female patients had full-thickness rotator cuff tears. Multivariable logistic regression analysis identified acromial morphology, age, and gender as independent multivariate predictors of rotator cuff pathology. Age, acromial morphology, and gender all have an independent association with rotator cuff pathology.