The Libyan market suffers a huge deficit of gasoline. More than 70 % is imported from international market. National oil Corporation (NOC) had signed a contract with EXXON Oil, British Petroleum and Eni Company to boost crude oil production in Libya. It is planned to drill 14 wells in Gulf Sirt offshore to enhance production of natural gas and crude oil in future. In this paper, a major petroleum refinery is to be built in Sirt to utilize a portion of the suggested crude oil from proposed Gulf Sirt offshore plant with Sharara crude to eliminate the deficit of the gasoline in Libyan local market. HYSYS software is used to model a new refinery of 500,000 barrels per day to be built in Sirt in order to produce LPG, naphtha, kerosene, gas oil and fuel oil for local and international market. Downstream units are also simulated to produce the enhanced products with international specifications. The refinery will be able to produce more than 177,000 bbl/day of gasoline which will be able to satisfy local needs of gasoline in Libya. Other products include LPG, kerosene, gas oil and fuel oil will satisfy future local demands and the rest will be imported to world markets.......................... Keywords:........... Crude oil refinery, HYSYS simulation, Gulf Sirt offshore, Sharara crude, Gasoline deficit.