Wear behavior of WC based nanocomposite cutting tool when high speed cutting ductile cast iron was investigated. Orthogonal cutting tests were carried out on a CA6140 lathe using three speeds, namely, 100, 215 and 287m min-1. The WC based nanocomposite tool is found to be superior to cemented carbide tools (YG8). The tool life is prolonged 60% as compared to cemented carbide, as the width of the wear land (VB), which was monitored at selected time intervals. Meanwhile, the topography of worn surfaces was scanned by a profilemeter. Wear characterization of the rake face and the flank surfaces as well as of the collected chips was conducted using a scanning electron microscopy (SEM). Results showed that distinctive traces of single abrasive tool wear event were found on the rake face of the tool, additionally, the adhesion wear is the main wear mechanism in the flank face of the tool. However, the extent of improvement in tool life depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates.