The Scottish Motor Neuron Disease Register (SMNDR) is a prospective, collaborative, population based study of motor neuron disease (MND) in Scotland. The register started in January 1989 with the aim of studying the clinical and epidemiological features of MND by prospectively identifying incident patients. It is based on a system of registration by recruitment from multiple sources, followed by the collection of complete clinical data and follow up, mainly through general practitioners. In this report the register's methodology and the demography and incidence data for the first year of study are presented. One hundred and fourteen newly diagnosed patients were identified in 1989 giving a crude incidence for Scotland of 2.24/100,000/year. Standardised incidence ratios showed a non-significant trend towards lower rates in north eastern regions and island areas.