This paper reports the fabrication process and field emission characteristics of high aspect ratio micropatterned diamond edge emitter cathode. An edge-shaped geometry has the advantage of providing large number of emission sites along the edge as determined by the microstructure of the edge surface. This is studied by fabricating emitter arrays of edges with three different lengths and comparing their emission behavior in a diode configuration. The edge emitter arrays were fabricated on silicon wafers by a mold transfer technique using conventional silicon micropatterning and etching techniques.The emission current was found to be function of length of the edge, with the longest edge showing the highest emission current. The turn-on field was observed not to be significantly affected by the length of the edge. We also report excellent high temperature field emission characteristics of diamond edge emitters. The field emission behavior was found to be temperature insensitive up to 300 °C with negligible reverse leakage current.