In view of the increasing medicolegal implications of advice given to patients, in particular the apparent increasing frequency of requests for advice about whether patients are fit to drive, a review was made of the literature, the law and the views of the major motor insurers. A patient should be advised when it is not safe to drive. If he disregards this advice and drives, he would be breaking the law and would not be covered by his insurance. Whilst recovering from an injury or an operation, a patient may not be as physically able as before but he may still be fit enough to drive. When it is considered that the patient's disability is more than about 3 months he should be advised to inform his insurers and to act in accordance with their response. On the other hand, when it is felt that the patient's disability is short-term, he should be advised that he is fit to drive but that he should be careful during the early stages. Provided that the patient feels safe to drive and drives carefully, he should be acting within the law, and should be covered by his existing insurance. In doubt, the patient should contact the Driver, Vehicle and Licensing Centre and his insurers and act accordingly. Doctors should record their advice in the patient's notes and should remember that the patient may be driving vehicles other than a car.