Effects of indoor environment on the performance of creativity and productivity were studied in a simulated office with an outdoor airflow rate of 5 or 20 L/(s·p), with other environmental parameters constant. The research was conducted with twenty subjects performing a series of computerized tasks, consisting of creativity tasks (Compound Remote Associate (CRA), Alternative Uses Task (AUT), and Toy Construction Task (TCT)), productivity tasks (typing and arithmetic), mood state and perceived IEQ questionnaires. Subjects self-assessed that they had a clearer head (p<0.049), perceived fresher air and exerted less effort under the higher ventilation rate (HV). Slightly increasing tendency was observed in the performance of CRA, TCT and productivity tasks with HV, although, none of the differences were statistically significant. The test outcomes indicated that short-term exposure to increased ventilation improved certain self-reported symptoms but did not significantly improve creativity or productivity performance.