**Abstract**

The purpose from this work is the investigation for dosimetric parameters of the two new BEBIG sources, 60Co and 192Ir used in high-dose-rate brachytherapy. According to the full report of AAPM and ESTRO; air-kerma strength, dose rate constant, radial dose function, and 2D along & away dose rates tables were calculated. Moreover, a comparison was made between the calculated dosimetric parameters for the HDR sources simulated in this study. We used the MCN-PX to investigate the dosimetric parameters of both sources. The geometry of each source was defined in the input program of MCNPX, and each simulation was performed with an appropriate number of particle histories to get an acceptable Type A statistical uncertainty. The results obtained were tabulated and presented in graphical format; these results show a good agreement with other previous studies. The comparison made between the two simulated sources in this work shows a minor difference observed in the generated 2D along & away tables for complementing the commissioning of these sources within a TPS. This difference is considered negligible by the clinical specialists.

**Keywords:** Co-60 versus Ir-192, Monte Carlo investigation, dosimetric comparison, HEBD working group
