The present work presents experimental results of subcooled flow boiling heat transfer phenomena in minichannels. The experiments were conducted with high surface tension liquid (water), which clearly indicates that inertial effects are important for both momentum and thermal transport in minichannels. The test section is a horizontal AISI 316 stainless-steel minitube with internal diameter of 1.13 mm with uniform heated length of 250 mm and the tube is heated by AC electric current. The variation in wall temperature and pressure drop gives an indication of the different boiling regions along the axis of the horizontal tube. Based on sudden oscillations of the pressure drop and wall temperature, onset of nucleate boiling (ONB) is identified in the tube. During ONB, pressure drop and the fluctuations of fluid outlet temperature are observed near the exit of the test section. Predictive models for ONB were evaluated and Kandlikar's ONB model was found to agree well with the present data. Comparisons of experimental heat transfer coefficient in the subcooled boiling regime with the existing correlations are also presented. © 2015 Copyright Taylor and Francis Group, LLC.