The present paper describes how to apply the Chebyshev orthogonal collocation technique to solve steady-state and unsteady-steady two-dimensional problems. All problems are solved using one single computer algebra, Mathematica ß . The problems include: (1) steady-state heat transfer in a rectangular bar, (2) steady-state flow in a rectangular duct, (2) steady-state heat transfer in a cooling cylindrical pin fin, (4) steady-state heat conduction in an annulus, (5) unsteady-state heat transfer in a rectangular bar, and finally (6) unsteady-state diffusion reaction system. Whenever possible the results obtained with orthogonal collocation are compared to the analytical solution in order to validate the applied numerical technique. ß 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:144-155, 2016; View this article online at wileyonlinelibrary.com/journal/cae;