The article presents the results of experimental investigations to determine the effect of active surface morphology of grinding wheels with a zone-diversified structure on the form and size of chips generated during traverse internal cylindrical grinding of 100Cr6 steel. In the grinding process involving grinding wheels with a zone-diversified structure, chip formation phenomena differ in the rough and finish grinding zones of the tool. In order to expand one’s knowledge of this phenomena, the microtopography measurements of the grinding wheel active surface in the rough and finish grinding zones were made, as well as scanning electron microscopic observations of these areas after the dressing cut and following internal cylindrical traverse grinding. The conducted studies showed that chips in the rough grinding zone of the grinding wheel active surface are usually several hundred micrometers in length. In the finish grinding zone, however, mainly micro-chips were generated whose length does not exceed 100 µm (usually around 10 µm in length). In the rough grinding zone, shearing-type and flowing-type chips dominate with a few examples of spherical melted chips. Moreover, in the finish grinding zone, mainly slice-type and knife-type micro-chips were observed.