The weather conditions in Kuwait impose a difficult HVAC building operation due to the hot and arid climate. Most of the time, high ambient temperatures in Kuwait exceed 48° C, which result in difficult indoor comfort condition. Mosques are religious buildings with intermittent occupancy, due to their special cultural and religious requirements. In fact, prayers schedule is scattered throughout five daily times, with a maximum use around noon times on Fridays only. In addition, the number of mosques is increasing, due to population growth, and imposes high electrical load requirements on the public authorities in Kuwait. This paper demonstrates and analyzes thermal behavior of a typical mosque in the state of Kuwait. An energy audit is performed using state of the art building energy simulation software (Visual DOE 4.1). The simulation tool is intended to analyze the thermal behavior of the audited mosques and is used to asses potential energy conservation opportunities for future mosque design in Kuwait. Data collection including drawings, site visits and total daily kWh monitoring are performed to carry out the simulation analysis. It is found that an annual energy use savings up to 72% can be achieved through improvements of buildings envelope designs and operating strategies. In addition, life cycle cost LCC analysis is performed to make economical assessment of the energy conservation measures that are evaluated in this study. It was found that a LCC saving around 40% can be achieved with a simple payback period of less than 4 years.