Aches and pains are a common problem in the elderly and often a positive auto-antibody result is difficult to interpret in the given clinical setting. We studied 96 unselected hospitalised Oriental elderly aged 65 years and above to determine the prevalence of auto-antibodies and their clinical significance. Anti-nuclear antibody (ANA) was positive in 33%; commonest titres were low (i.e. 1:40); commonest patterns were speckled and homogeneous; 44% had no known cause for a positive result apart from their age; 37% were taking drugs known to be associated with a positive ANA and 19% had both a disease and a drug known to be associated with a positive ANA. Rheumatoid factor (RF) was positive in 16%; 47% had titres < or = 40 IU/ml and 87% had no known cause of positive RF. Other auto-antibodies tested were negative. We conclude that the prevalence of auto-antibodies in the hospitalised Oriental elderly are common and of no clinical significance if accompanying features of an auto-immune disease are absent.