The speeds of sound in 1,2- and 1,3-propanediol have been measured in the temperature range from (293 to 318) K at pressures up to 101 MPa by the pulse-echo-overlap method. The densities of the tested propanediol isomers have been measured in the temperature range from (283.15 to 363.15) K under atmospheric pressure with a vibrating tube densimeter. From the experimental results, the densities, isobaric heat capacities, isobaric coefficients of thermal expansion, isentropic and isothermal compressibilities, as well as the internal pressure as a function of temperature and pressure have been calculated. The effects of pressure and temperature on the above quantities are discussed. A new temperature dependence of the heat capacity for 1,3-propanediol is reported too.