This work presents an experimental study on two-phase flow pressure drop for R-407C in a smooth copper tube, alternating a 4.5 mm with a 8.0 mm inner diameter. Data set were collected in different experimental conditions, such as adiabatic and diabatic (4 kW m. −2), evaporation pressures (10.0 bar and 12.0 bar), mass flux (from 180 kg m s. − − 2 1 to 500 kg m s. − − 2 1). As a consequence of the experiments and the database from literature review, the effects of vapor qualities, diameters, mass fluxes and saturation pressures on the two-phase flow pressure drop were studied. The present experimental data was compared against 18 different correlations. Results showed that Cicchitti et al. and Sun and Mishima correlations provide the best results.