In this paper, natural convection heat transfer from two horizontal heated cylinders in a rectangular cavity is analysed, both by computational and experimental method. The two horizontal cylinders are located one above the other in the vertical symmetry plane of the cavity. A finite-element procedure based on the streamfunction-vorticity formulation of the momentum and energy equations is employed for the numerical solution of the flow and thermal field. Computed results include plots of the flow and thermal field patterns, and plots of the distribution of the local Nusselt number on the cylinder surfaces. The experimental apparatus consists of a test cell, made by a rectangular enclosure filled with air, and of a holograms