The densities of the binary mixtures n-heptane + isomeric chlorobutane have been determined in a wide range of both temperatures and pressures (T = 283.15-323.15 K, p = 0.1-65.0 MPa). From experimental densities different excess volumetric properties have been estimated. The results have been discussed taking into account both molecular interactions and structural effects operating in the mixing process. In addition, the densities of the mixtures have been satisfactorily predicted using the VTPR model. (C) 2015 Elsevier B.V. All rights reserved.