A retrospective investigation of 51 cases of sudden unexplained death syndrome (SUDS) reported to the Medico-Legal Centre in Dammam during the period January 1995 to June 1997 was carried out. The vast majority of SUDS victims were Indians (43%). The study reports SUDS in non-East Asian subjects, including indigenous Saudis, for the first time. Autopsy examination was carried out on 22 subjects and did not reveal any significant pathological lesions which could fully explain the sudden death. However, seven cases showed mild to moderate cardiac hypertrophy (of whom two had mild to moderate coronary stenosis), and another four showed a similar degree of coronary narrowing without any evidence of myocardial hypertrophy. Severe pulmonary congestion and alveolar haemorrhage were noticed in 18 of the autopsied cases. Microbiological tests were performed on different specimens from 27 subjects and showed significant bacterial growth in seven cases. The paper reviews different hypotheses explaining SUDS and suggests areas of further study in such deaths.