The Dix-Hallpike manoeuvre is widely used in the diagnosis of positional vertigo and is regarded as safe. The manoeuvre involves a degree of neck rotation and extension, and consequently one might expect there to be some patients, particularly those with neck problems, in whom the manoeuvre is contraindicated. The term 'neck problem', however, encompasses a whole range of conditions, including soft tissue disorders, cervical spondylosis, prolapsed intervertebral disk, and severe rheumatoid arthritis with cervical instability. These in turn will give rise to a variety of symptoms, which will vary from minimal pain or stiffness to severe pain or complete immobility, and, in some cases, neurological deficit. Clarification is therefore needed to establish the point at which any neck pain or stiffness ceases to be a minor problem and becomes a contraindication to performing the Dix-Hallpike manoeuvre. This paper clarifies this issue by discussing the issue of absolute contraindications and proposing a simple functional assessment of neck mobility which can be performed prior to performing the Dix-Hallpike manoeuvre. Relative contraindications such as back pathology, vertebrobasilar ischaemia (posterior circulation ischaemic disease), nerve root compression and medical fitness are also discussed.