A 72-year-old female patient presented to our consultation for discomfort on her left shoulder. Interrogation revealed a fall over 2 years ago with reception on her left shoulder. For lack of means, the patient never seen a doctor nor had radiological assessment. After few weeks of traditional splinting, she slowly returned to regular activities in a gradual fashion. Physical examination found no pain in active and passive mobilization of her shoulder, limited decrease in ROM, mostly of internal rotation, and good trophicity of deltoid and periscapular muscles. However, Neer and Hawkins manoeuvres were positive indicating a sub-acromial impingement. AP radiographs in neutral and external rotation revealed a non-union of a neglected humerus surgical neck fracture and aggressive acromion type II of Bigliani. Patient underwent arthroscopic sub-acromial decompression with good functional outcomes. Proximal humerus non-union was not addressed with no complaints from our patient. The prevalence of non-union after a proximal humeral fracture varies from 1.1% to 10.4 according to different series reported and the main risk factors of its occurrence are decreased head-shaft angle, increased head-shaft translation and smoking.