An experimental investigation was carried out for predicting the critical heat flux (CHF) of convective boiling of saturated liquids for a round jet impinging on the horizontal jet stagnation zone. The model of maximum liquid subfilm thickness based on the Helmholtz instability was used to derive a semi-theoretical equation. The experimental data of four liquids: water, ethanol, R-113 and R-11 were employed to determine the correlation factor. The impact velocity ranged from 0.5 m/s to 10 m/s and the diameters of the jet nozzle ranged from 3 mm to 10 mm. A semi-theoretical correlation was proposed for predicting CHF of convective boiling for saturated liquids jet impinging on the stagnation zone in a wide range. (c) 2005 Published by Elsevier Ltd.