Knee pain is a common complaint in clinical practice, and pes anserinus tendino-bursitis syndrome (PATB) has been frequently diagnosed based only on clinical features that may cause equivocal interpretations. Patients complain of characteristic spontaneous medial knee pain with tenderness in the inferomedial aspect of the joint. Studies with different imaging modalities have been undertaken during the last years to identify whether these patients suffer from bursitis, tendinitis, or both. Nevertheless, little is known regarding the structural defect responsible for this disturbance. Due to these problems and some controversies, we suggest the term "anserine syndrome" for this condition. Diabetes Mellitus is a known predisposing factor for this syndrome. Overweight and osteoarthritis seem to represent additional risk factors; however, their role in the pathophysiology of the disease is not yet understood. Treatment includes non-steroidal anti-inflammatory drugs, physiotherapy, and injections of corticosteroid, with highly variable responses, from 10 days to 36 months to achieve recovery. The lack of knowledge about its epidemiological, etiological, and pathophysiological aspects requires future studies for this common and intriguing disorder.