In this work, the cutting performance of CBN insert was investigated in terms of surface roughness and tool wear in turning of hardened (60 HRC) PMD-23 powder metallurgical steel. The turning tests were performed with three different cutting speeds, feed and depth of cuts in dry cutting condition. Analysis of Variance (ANOVA) was performed in order to determining of the effect of cutting parameters on the average surface roughness (Ra). The experimental results and indicated that the depth of cut was most significant parameter on changes in Ra. Furthermore, images of cutting insert used in turning tests were taken using Scanning Electron Microscope (SEM) for determining of the wear types and its mechanisms. According to the image investigation, crater wear and slightly flank wear were observed in cutting insert. Depending on the increase in feed and depth of cut values Ra values were increased. ANOVA results showed that the most influential parameter is depth of cut on the values of Ra and the second influential parameter is feed.