Freezing of gait (FOG) is a disabling condition in older people. It is common in Parkinson's disease (PD) and other parkinsonian syndromes. The assessment of this condition poses challenges due to its episodic and transient nature and its frequent association with cognitive impairment. The pathophysiology of FOG is complex and poorly understood. Morphological brain imaging is of limited value in the evaluation of FOG, and functional imaging techniques are currently being developed to study the phenomenon. The treatment of 'off' time FOG in PD is relatively straight forward, but 'on' freezing in PD and FOG associated with other conditions may be difficult to treat. FOG is a strong risk factor for falls and adversely affects the quality of life of patients and carers. A multidisciplinary team approach is essential for optimum management.