Density of rocket propellant (RP-1 fuel) has been measured with a constant-volume piezometer immersed in a precision liquid thermostat. Measurements were made in the temperature range from 301 to 745 K and at pressures up to 60 MPa. The uncertainty of density, pressure, and temperature measurements were estimated to be 0.1%, 0.05%, and 15 mK, respectively. The measured values of density were compared with the data reported in the literature and with the values calculated from a surrogate mixture model (equation of state). The average absolute deviation (AAD) between the present data and the values reported in the literature was 0.13%. (C) 2009 Elsevier Ltd. All rights reserved.