Field investigations of target air pollutants at two of the most famous temples in Hong Kong were conducted. Each temple was investigated at two periods. One was the peak period, 1st or 15th day of Chinese lunar during which more pilgrims appeared at each temple for blessing and another was the non-peak period, non-1st or non-15th day of Chinese lunar. The target pollutants included particulate matters (PM10, PM2.5), carbonyl compounds, carbon monoxide (CO), nitrogen oxides (NOx), methane (CH4), non-methane hydrocarbon (NMHC), organic carbon (OC), elemental carbon (EC) and inorganic ions (Cl-, NO3-, SO4 2-, Na+, NH4 + and K+). The pollutant levels of the two temples during peak periods were shown to be significantly higher than that during non-peak periods, which implies the existence of health impact on those visitors staying in the temples during peak periods.