Quadrilateral Space Syndrome (QSS) in a rare condition but with high clinical relevance. QSS is characterized by compression of all the neurovascular structures that pass through quadrilateral space. Diagnosis is difficult and often this condition remains misdiagnosed because clinical presentation is variable, there are no specific clinical tests and imaging is not so accurate. Symptoms can mimic lots of other shoulder conditions and vary from non-specific pain to neurovascular disorders. Usually patients are young (less than 40 years old), active and report symptoms especially in abduction-external rotation movements. Treatment should always start with conservative procedure (nonsteroidal anti-inflammatory drugs, physical therapy, injections), delaying surgery only in case of failure.