Laminar natural convection of a nanofluid consists of water and copper in a differentially heated parallelogrammic enclosure has been studied numerically using the finite volume method (FVM). Governing equations are solved over a wide range of Rayleigh numbers (10^{4}^{ }≤ Ra ≤ 10^{6}), skew angles (−60 deg ≤ *Φ* ≤ +60 deg), aspect ratios (0.5 ≤ AR ≤ 4), and solid volume fractions (0 ≤ *φ* ≤ 0.2). Effects of all these parameters on flow and thermal fields are presented in form of streamline, isotherm contours and average Nusselt number. It is shown that the heat transfer rate increases remarkably by the addition of copper-water nanofluid and the shape of the convection vortices is sensitive to the skew angle variation.