Early diagnosis of rheumatoid arthritis (RA) combined with early initiation of an appropriate treatment regimen is acknowledged as an important factor in improving clinical outcomes in patients with RA. Early diagnosis allows treatment intervention to occur sooner in order to inhibit the progression of structural joint damage as well as providing improved patient quality of life. Unfortunately, early diagnosis has been challenging due to the non-specific signs and symptoms associated with many polyarthropathies and the lack of accurate definitive diagnostic tests that can accurately classify RA at presentation. The emphasis on early diagnosis has fueled the need for powerful, sensitive, non-invasive imaging techniques that not only accurately define RA and give an indication of prognosis, but can also serve as a tool to monitor long-term treatment outcomes. This article reviews the potential uses of magnetic resonance imaging as a tool for the classification, documentation, and clinical monitoring of RA.