In this study, the effect of microwave radiation on grindability of Turkish lignite has been investigated. Turkish lignite (-15 mm, 500 g) was treated by microwave (at a frequency of 2.45 GHz) in a Te010 single mode cavity using a pneumatic system to control the residence time of each sample in the cavity with high-electric-field-strength microwave energy at different power settings (in the range of 5-20 kW) for a short residence time (2 sec). In order to determine the grinding resistance of Turkish lignite samples treated by microwave ovens, the Hardgrove Grindability Test was applied for each treated and untreated sample and also the amount of fine product (-74 m) was evaluated and compared with each other. Experimental results have shown that significant increases in grindability were achieved when the lignite samples were exposed to microwave radiation. The Hardgrove Grindability Index of samples and the amount of fine product increased up to 123 and 117%, respectively.