Certain gear failure mechanisms are strongly affected by tribological effects on the flank surface. Here, the sliding conditions in the tooth contact can play a decisive role. Unlike for external gears, a positioning of pitch point C outside of the active profile is possible for internal gear designs. This allows to completely avoid negative sliding either on the planet or the ring gear. Furthermore, the local amounts of specific sliding over the active path of contact, mainly relevant for slow speed wear, can be modified for such gear designs. In recent investigations at FZG, a distinct influence of unbalanced sliding conditions was confirmed, showing a significant increase of the pitting load capacity by avoiding contact areas of negative sliding on the ring gear, while an exposure to negative sliding only leads to a reduction of the pitting resistance. However, systematic results on the wear resistance of such internal gear designs with the pitch point positioned outside of the active profile are not available. Existing wear calculation methods are mainly based on investigations considering external gears with balanced sliding conditions. Within this research, systematic theoretical and experimental investigations on the wear behavior of internal gears in different material pairings were performed. To investigate the influence of unbalanced sliding conditions, a reference geometry (balanced sliding) was compared to gear designs with pitch point below respectively above the active profile. Generally, the experimental results show a good correspondence with the state of the art and previous investigations. The results confirm the significant influence of the absolute specific sliding numbers on the local material removal due to wear. For the internal gear geometries with pitch point outside of the active profile, a more distinct running-in wear behavior could be observed in the pairing with a through-hardened respectively nitrided ring gear. Furthermore, a comparison between the experimental results and theoretical simulations based on a local wear approach was made.