Hypertrophic cardiomyopathy, with myocardial fibre disarray, may occur in 20-25% of cases with Noonan's syndrome. However, dilated cardiomyopathy has not previously been reported. We describe a patient with Noonan's syndrome who presented with typical features of dilated cardiomyopathy with biventricular enlargement and left ventricular ejection fraction of 0.16. Endomyocardial biopsy showed focal interstitial fibrosis and fibre hypertrophy but no disarray. This is the first report in the world literature of an association between Noonan's syndrome and dilated cardiomyopathy. It is possible that this linkage with dilated rather than hypertrophic cardiomyopathy is more common in the Chinese.