Frying is an important indoor air pollution source. It may cause chronic health effects on cooks. This study measured indoor air concentratinos of volatile organic compounds (VOCs), aldehydes, particulate matter, CO and CO2 in a small scale restaurant kitchen before, during, and after frying with a margarine produced specifically for frying. Both sampling and monitoring strategies were employed. Individual VOCs, aldehydes, and PM2.5 concentrations were determined by sampling. Total VOCs, PM10, CO, and CO2 concentrations were determined using a monitoring device. Temperature and relative humidity were also monitored as comfort variables in addition to CO2. Two campaigns were conducted. In Campaign-1 real working conditions were studied. In Campaign-2 only potatoes were fried with varying amounts. N-heptane, ethyl acetate, nonanal, and n-octane were the realtively higher concentration compounds in both campaigns. The increase in PM10 concentrations, however, was much more pronounced: about five times higher when the lowest concentration observed in the very beginning and the peak concentration during frying are compared, and two times higher when the average concentrations are compared. CO and CO2 concentrations were relatively low, and temperature and relative humidity levels were generally in the comfort zone. The observed PM10 concentrations during frying and the average PM2.5 concentrations (80-250 μg/m3) of 4-hr period that covers the all three periods (before, during, and after) in Campaign-1 indicate that chronic health effects are probable for cooks who frequently cook by frying with the frying margarine.