Pressure-density-temperature (p rho T) data for three types of ionic liquid, [emim] [lactate], [(C2H4OH) (CH3)(3)N][lactate], and [bmim] [Cl], were measured with a bellows type dilatometer at temperatures up to 452 K and at pressures up to 200 MPa. The Tait equation could correlate the density data as a function of temperature and pressure to within an average relative deviation (ARD) of 0.014 %. The thermal expansion coefficients and the isothermal compressibilities were estimated with the Tait equation, and their variations with temperature and pressure, d alpha(p)/dT and dk(T)/dp, were found to be negative. Lattice type equations of state were applied to correlate the data. The densities could be correlated to within an ARD of 0.21 % and 0.067 %, for the Sanchez-Lacombe equation of state and the epsilon-modified Sanchez-Lacombe equation of state, respectively. The equation-of-state parameters determined should be useful in estimating the properties of mixtures and in estimating the phase equilibria of binary and multicomponent systems.