OBJECTIVE : Over the past years, Monte Carlo codes have widespread use in the radiation research field. Radiography tally of MCNPX Monte Carlo code can be a popular and applicable tool for simulation of radiography images. However, validation is the most important prerequisite before using its results. METHODS : Herein, validation of MCNPX radiography tally with experimental results based on the output image parameters has been investigated. Three cubic phantoms with different thicknesses and aluminum, water, and acrylic inserts were studied. The effects of uniformity correction, the detector efficiency of X-ray in different energies, as well as noise caused by a high statistical error in the simulation were also evaluated. RESULTS : Based on the proposed protocol to correct the error and uniformity of simulated images versus experimental ones, the maximum difference of less than 5% was achieved. CONCLUSIONS : Consequently, using the presented method with fewer steps than previous similar works, the MCNPX radiography tally of Monte Carlo code is a useful and validated tool for medical investigation of radiology images.