To answer to an increasing need in the lighting simulation domain, the CIE technical committee 3.33 defined recently a set of test cases to be used for assessing the accuracy of lighting computer programs. These test cases have the advantage of avoiding or reducing the uncertainties in the validation reference data by using simple analytical scenarios or by applying reliable experimental protocols. This paper presents an application example of these test cases to two existing lighting computer programs. Thirty-two different testing scenarios were used covering different aspects of the lighting simulation domain: direct artificial lighting, direct daylighting and diffuse reflections and interreflections. This work showed the usefulness of the CIE simple test cases in identifying the strengths and weaknesses of the tested programs and the accuracy and the capabilities of the programs in simulating different aspects of the lighting propagation were clearly verified. However, the need to expand the CIE set of test cases to other aspects of light and daylighting design has been noted. (c) 2006 Elsevier B.V. All rights reserved.