The impact of joint frequency and relative joint orientation to the presplit have been examined in medium strong overburden rock from 6 pits of a large open cut coal mine in Central Queensland, Australia. The results of this study have shown for this rock type that there is a significant decrease in the presplit quality with increased joint frequencies and that presplit quality decreases with an increase of relative orientation from 5 to 30 degrees. These findings are consistent with theory presented in the literature.