The influences of edge effect on flow and temperature uniformities were investigated for oblique-finned structure on both planar and cylindrical heat source surface though numerical and experimental studies. The numerical simulation using CFD approach was employed to provide definitive information about the flow field distribution and flow mixing between the main and secondary channels. The flow field analysis showed that poor flow mixing exists in the draining region and filling region, while the flow regime between the middle regions is not influenced by the edge effects in the blockaded cylindrical oblique fin heat sink. For regular cylindrical oblique fin heat sink, the flow fields in both the main and secondary channels are distributed uniformly in the spanwise direction. The local temperature distribution curves for blockaded cylindrical oblique fin heat sink are shown to have a uniquely concave shaped due to edge effects. Interestingly, a uniform and lower surface temperature distribution for regular cylindrical oblique fin heat sink are observed as a result of improved flow mixing due to the absence of the edge effects. These studies prove that cylindrical oblique fin heat sink is an effective cooling solution for cylindrical heat sources, and this can provide insights for designers interested in oblique fin heat sink or other similar designs. (C) 2013 Elsevier Ltd. All rights reserved.