The paper presents experimental results of dryout of four fluids in two small diameter silver tubes with inner diameters of 1.15mm and 2.3mm, respectively. The experiments have been accomplished for a wide range of quality variation, mass flow rate and heat fluxes, i.e. x=0.65–1.0, G=40–900kg/m 2 s and q=20–220kW/m 2 . The effects of various parameters such as mass flux, vapor quality and internal diameter on the dryout were considered. The results show that the dryout heat flux increases with the increase in mass velocity, with the decrease of vapor quality and with the increase of tube diameter. Utilized has been modern infrared technique for the measurements of wall temperature. Based on the obtained experimental data-base the correlation for prediction of critical heat flux (CHF) in the minichannels was proposed, which was compared with the predictions obtained by other published correlations.