Raynaud's phenomenon is a common paroxystic vasomotor disorder. Diagnosis is easily made based on white fingers caused by cold. Aetiological evaluation must distinguish between functional disorders (primary Raynaud's phenomenon or Raynaud's disease) and secondary Raynaud's phenomenon. Initially, physical examination as well as nailfold capillary microscopy are sufficient for the diagnosis of bilateral Raynaud's phenomenon. Prescription of other investigations is guided by the results of this first evaluation. Progressive systemic sclerosis is the first hypothesis if the bilateral vasomotor disorder does not satisfy the criteria for primary Raynaud's phenomenon. Unilateral Raynaud's phenomenon is much less common and always secondary to local or regional vascular disease. Treatment of Raynaud's phenomenon must be adapted to the level of discomfort and to the cause of the vasomotor disorder. Prescription of drugs must be restricted to the most serious cases.