Primary Raynaud's phenomenon (RP) is a relatively common disorder. Most patients with primary RP have only mild symptoms and do not develop complications. Distinguishing primary from secondary RP is important with respect to complications, and for prognosis and treatment. Secondary RP mainly manifests as part of systemic connective tissue disease. About 13% of patients diagnosed initially as having primary RP develop a systemic disorder within the following few years. Both auto-immune serology including antinuclear antibodies (ANA), and capillaroscopy are important diagnostic tools if one suspects the existence or development of a systemic disorder. Calcium antagonists are the cornerstone of RP pharmacotherapy.