Abstract In this article, the excess molar volumes and partial molar volumes of components of the binary system octyl methoxycinnamate (OMC) + ethyl acetate (AcOEt) were investigated from density measurements on the entire range of mass fractions for this system at 298.15, 303.15, 308.15, 313.15, and 318.15 K. The results of excess molar volumes were fitted by the Redlich–Kister equation using third degree polynomials. The system exhibited negative excess volumes (up to −0.926 cm3 mol−1 at 318.15 K), probably due to interactions like dispersion forces between unlike molecules or some differences in the molar volumes of pure components. The effect of temperature on the different volumetric properties studied was also analysed. Besides, the volumetric thermal expansion coefficients were also calculated finding values varying from 7.53 × 10−4 K−1 for pure OMC up to 1.38 × 10−3 K−1 for pure AcOEt at 308.15 K. Keywords: octyl methoxycinnamateethyl acetatebinary liquid mixturesexcess volumespartial volumes Acknowledgements We thank the Department of Pharmacy of Universidad Nacional de Colombia for facilitating the equipment and laboratories used in this investigation.