The fuel loss at gas stations is one of the main sources of volatile organic compounds in the ambient air. The study shows 52000 liter of gasoline per day is lost from the gas stations across the city of Tehran. Each station losses approximately 415 liters per day, which makes the area on and around the gas stations polluted. In this study, the BTEX were measured at two gas stations and 20 main cross streets, during summer and winter. The results indicated Benzene concentration is higher than the ambient air limits for both the gas station areas as well as the 20 measured places across the city. The average concentration of Benzene in the gas stations were between 8 to 16 times higher than the threshold limit value — time weight average for work area, and 250 to 500 times higher than the ambient air standard. The average concentration of Benzene near the traffic areas were 60 times higher than ambient air standard. Also we studied the ways to control gasoline vapor. Cooling the vapor has been experimented. The results show, 50% of vapor in 0—6°C could be recycled.