This article is devoted to investigating the mixed convection arising from two equally hot circular cylinders embedded in a square cavity of adiabatic surfaces. This cavity is filled with an incompressible fluid and contains single entry and outlet orifices. The heated cylinders are assumed to be arranged side‐by‐side with a fixed gap within the square cavity. Based on some simplifying assumptions, the nonlinear governing equations that express the principle of conservation of mass, momentum, and energy are obtained and numerically solved using a Computational fluid dynamics package ANSYS‐CFX with finite volume technique. Pertinent results showing the roles of embedded parameters such as Richardson number (Ri = 0 to 1) and Reynolds number (Re = 1 to 40) at Prandtl number (Pr = 1) on the overall fluid flow and temperature patterns are graphically depicted in the form of representative streamlines and isotherms. The values of average Nusselt number and total drag coefficient (CD) for both representative cylinders are also computed and discussed. Generally, an increase in buoyancy force augments the effectiveness of heat transfer only of the down cylinder. Also, a rise in Re and/or Ri numbers augment the flow instability.