BACKGROUND: There has been a Human Volunteer Programme at the British chemical weapons research facility at Porton Down since the First World War, in which some of the participants were exposed to chemical warfare agents. AIM: To identify any striking specific morbidity patterns in members of the Porton Down Veterans Support Group (PDVSG). METHODS: A self-completed postal questionnaire was prepared including health immediately after the visits to Porton Down, subsequent diagnoses and hospital admissions, symptoms in, and after, the first 5 years after the visits, fatigue symptoms and current quality of life, measured using the SF-36. RESULTS: Responses were received from 289 of 436 (66%). Results reported here relate to 269 male respondents of mean age 66.8 years. Sixty-six per cent reported their first visit to Porton Down in the 1950s. The most common diagnoses or hospital admissions reported were diseases of the circulatory system. In the first 5 years after their visits the most common symptoms were headache, irritability or outbursts of anger and feeling un-refreshed after sleep. In the later period, most common symptoms were fatigue, feeling un-refreshed after sleep and sleeping difficulties. Sixty-five per cent met the definition for a case of 'fatigue'. Current quality of life dimensions were consistently lower than age-specific estimates from general population samples. CONCLUSIONS: Members of the PDVSG responding to this survey reported poorer quality of life than the general population. Despite there being no clear pattern of specific morbidities, we cannot rule out ill-health being potentially associated with past experience at Porton Down.