A recently proposed density-based phase envelope construction method (Nichita, Fluid Phase Equilib. 478, 100-113, 2018) is adapted to account for capillary effects. The set of saturation point equations is selected such as both the zero tangent plane distance (TPD) function (in terms of component molar densities and temperature) and the Young-Laplace equation are honored. The set of variables and potential specifications includes mixture molar density, temperature and the modified equilibrium constants (defined as the ratios of reference to incipient phase component molar density). The number of equations and the variables are the same as in the bulk fluid case. The density-based method including capillary pressure is not dependent on the thermodynamic model; any pressure-explicit equation of state and volume-explicit interfacial tension model can be used. The equation of state (EoS) must not be solved for volume and the elements of the Jacobian matrix have simpler expressions than those in conventional (pressure-based) methods. A code for phase envelope construction of bulk fluids can be easily modified by adding the capillary terms to the residual functions and Jacobian matrix. The additional partial derivatives of capillary terms have very simple expressions due to the explicit in volume form of the interfacial tension model. Unlike in conventional formulations, negative pressures in the reference phase can be handled. The proposed method is tested for several hydrocarbon mixtures, ranging from natural gases to heavy oils. As compared to a bulk fluid, under capillary pressure influence the bubble point pressures are suppressed and the dew point locus is expanded, with a shift of cricondentherm points towards higher temperatures. For the mixtures investigated, the computational results are practically identical to those reported in the literature. The computational procedure is robust, there are no problems neither in crossing the critical region (where interfacial tensions are very low) nor at important negative pressures and for very large capillary pressures (of the order of hundreds bar in some test examples). (C) 2019 Elsevier B.V. All rights reserved.