Indoor air quality has a great impact on human health. Cooking, in particular frying, is one of the most important sources of indoor air pollution. Indoor air CO, CO 2 , particulate matter (PM), and volatile organic compound (VOC) concentrations, including aldehydes, were measured in the kitchen of a small establishment where a special deepfrying margarine was used. The objective was to assess occupational exposure concentrations for cooks of such restaurants. While individual VOC and PM 2.5 concentrations were measured before, during, and after frying events using active sampling, TVOC, PM 10 , CO, CO 2 , temperature, and relative humidity were continuously monitored through the whole period. VOC and aldehyde concentrations did not increase to considerable levels with deep-frying compared to the background and public indoor environment levels, whereas PM 10 increased significantly (1.85 to 6.6 folds). The average PM 2.5 concentration of the whole period ranged between 76 and 249 μg/m 3 . Hence, considerable PM exposures could occur during deep-frying with the special margarine, which might be sufficiently high to cause health effects on cooks considering their chronic occupational exposures.