Prevalence of rotator cuff tears increases with advancing age (Ellman et al). In spite of proximal humeral fractures being common in the elderly, the influence of a coexistent rotator cuff tear on outcome has, to our knowledge, not been previously investigated. This study prospectively assessed whether the presence of a rotator cuff tear in association with a proximal humeral fracture influences functional prognosis. 85 patients treated conservatively for proximal humeral fractures were evaluated prospectively with Ultrasonography to determine the status of the rotator cuff. Every patient was managed by immobilisation of the arm in a sling for two weeks followed by a course of physiotherapy based on the Neer regime. Functional outcome was measured using the Constant shoulder score and the Oxford shoulder score, at 3-months and 12-months post injury. Sixty-six of the 85 patients were female. The fractures were equally distributed for hand dominance. There were 27 patients with an undisplaced fracture, 34 patients with Neer's Type II fracture and 24 patients with Neer's Type III and IV fracture. There were 43 patients with full thickness cuff tears and 42 patients with no cuff tear or a partial thickness tear. Full thickness cuff tears were much more frequent in the over 60 year age group, which is consistent with the known increased incidence of cuff tears with increasing age. The outcome scores at 3 and 12 months showed no statistically significant difference for either the Constant score or the Oxford score with regards to cuff integrity. Analysis of these scores showed no correlation between presence or absence of a full thickness cuff tear and shoulder function. The results of this study indicate that rotator cuff integrity is not a predictor of shoulder function at 12 months following proximal humeral fracture, as measured by outcome scores. This suggests that there is therefore no clinical indication for routine imaging of the rotator cuff in patients for whom conservative management is the preferred treatment option