The prevalence of left ventricular hypertrophy, glomerular hyperfiltration and retinovascular abnormalities was investigated in 43 black and 45 white children with essential hypertension. Whilst 36% of subjects had left ventricular hypertrophy, 49% had glomerular hyperfiltration and 50% had retinal abnormalities, no differences were found between blacks and whites. This pattern differs from that found in adult hypertensives.