Reflex sympathetic dystrophy (RSD) is a pain syndrome of unknown cause with well-defined clinical features that usually develop after minor or major trauma of a limb. Clinical symptoms include pain, swelling, changes in surface temperature, and an impairment of physical force and mobility. Among other trauma, arthroscopic procedures are known to precipitate RSD. In some patients, making differential diagnoses of complications after arthroscopy and RSD can be difficult based on clinical data. Multiphase bone scintigraphy is exceptionally useful in this setting, because the scintigraphic abnormalities in RSD, in contrast to all other differential diagnoses, are not limited to the site of the trauma and usually affect the entire extremity. This is fully illustrated by the case of a 45-year-old man in whose knee joint burning pain developed 1 week after an initially uncomplicated knee arthroscopy. The findings of initial scans and follow-up results during therapy are described.