The aim of the present study is to simulate a commercial contrast detail phantom - (CDRAD 2.0 phantom) used in the evaluation of both digital and analog radiographic units. This phantom is suitable for the estimation of low contrast resolution. The software phantom was developed in the Matlab 7.01 platform. The results of the software phantom were evaluated with the ones obtained on a digital radiographic unit (DIAGNOST Philips Medical Systems) and showed a very good agreement. The software phantom uses tabulated data for the X-ray spectra and attenuation coefficients in order to simulate the CDRAD images as well as the contrast details versus X-ray energy and phantom depth. This software phantom provides an easy, fast and reliable method for the evaluation of contrast detail in radiographic units (both digital and analog) with the use of a personal computer.