• On the basis of primarily consensus, due to lack of relevant clinical studies, the information obtained from the history and physical examination is the key to establishing a diagnosis and directing initial management of knee pain. • By applying history and physical examination findings to a diagnosis and management algorithm, clinicians can efficiently and effectively determine the potential cause of the knee pain. • On the basis of primarily consensus, due to lack of relevant clinical studies, the most important step of the evaluation of knee pain is to identify emergent conditions, including limb- and life-threatening conditions (eg, septic arthritis, osteomyelitis, and malignancy), hip pathology, or conditions associated with effusions.