The aim of this study was to document the incidence of postoperative shoulder stiffness (SS) after arthroscopic rotator cuff repair and evaluate the role of risk factors for its development. Seventy-five consecutive patients that underwent arthroscopic rotator cuff repair were included. The incidence of postoperative SS was prospectively investigated and the presence of 20 potential risk factors was documented retrospectively. The incidence of post-operative SS was 10.4%. All patients were women, and sex was significantly associated to pathology development (p=0.0067). The presence of gastroesophageal diseases was found to be significantly associated with post-operative SS development (p=0.0046). A significant association between the occurrence of post-operative SS and the presence of gastroesophageal diseases was identified. This finding, not yet reported in literature, deserves further investigation. The incidence of postoperative SS fell among previously reported ranges, with females significantly more affected than men.