Hyperandrogenism and exogenous glucocorticoid excess may cause unfavourable changes in the cardiovascular risk profile of patients with congenital adrenal hyperplasia (CAH). To evaluate the cardiac function in paediatric patients with CAH. Twenty-seven paediatric patients with CAH, aged 8-16 years, were evaluated by physical examination, electrocardiogram (ECG), conventional echocardiography, tissue Doppler imaging and two-dimensional (2D) myocardial strain (rate) imaging. Results were compared to 27 age- and gender- matched healthy controls. No signs of left ventricular hypertrophy or dilatation were detected on echocardiography. ECG revealed a high prevalence (25.9%) of incomplete right bundle branch block. Left ventricular posterior wall thickness in diastole (LVPWd) was significantly lower in patients with CAH compared to controls (5.55 vs 6.53 mm; P = .009). The LVPWd Z-score was significantly lower in patients with CAH yet within the normal range (-1.12 vs -0.35; P = .002). Isovolumetric relaxation time was significantly lower in patients with CAH (49 vs 62 ms; P = .003). Global longitudinal, radial and circumferential strain was not significantly different compared to controls. Global radial strain rate was significantly higher compared to healthy controls (2.58 vs 2.06 1/s; P = .046). Global longitudinal strain was negatively correlated with 24-hour blood pressure parameters. Cardiac evaluation of paediatric patients with CAH showed no signs of left ventricular hypertrophy or ventricular dilatation. LVPWd was lower in patients with CAH than in controls but within the normal range. A shorter isovolumetric relaxation time in patients with CAH may be a sign of mild left ventricular diastolic dysfunction.