Laterally Diffused MOSFET (LDMOS) are widely used in modern communication industry and other applications. LDMOS offers various advantages over conventional MOSFETs with little process change. In the present paper, an LDMOS device is modeled and simulated in SILVACO device simulator package using the ATHENA and ATLAS modules. The complete fabrication process is modeled and the device performance is simulated. The modeled device gives a 46 V breakdown voltage for a device gate length of 5μm. The device threshold voltage is 0.97V. The device characteristic are also simulated and presented.