IncensePolycyclic aromatic hydrocarbons Volatile organic hydrocarbons Heavy metals Abstract Incense burning in indoor environments is a common practice in many countries and communities in the world. In the present investigation one type of incense was used for the purpose of studying the quality and quantity of emissions released, both before and during burning with respect to volatile organic compounds including aldehydes. The polycyclic aromatic hydrocarbon (PAH) content and elemenal composition of air particulate matter and ash were also investigated. The study included controlled experiments in an environmental chamber as well as field tests. The results showed the presence of benzaldehyde, linalool, benzyl alcohol, phenethyl alcohol, formaldehyde, and acetaldehyde in the emissions of incense both before and after burning. Incense burning produced additional compounds, such as benzene, toluene, and diethyl phthalate. The concentrations of these compounds depended on the time of sampling. No PAHs were detected in air particulate matter after incense burning or in the combustion residue. Various elements were detected both in air particulate matter and combustion residue. The results confirm that incense is a potential source of indoor pollution which should be the subject of further study. the world. It is burned in houses, churches, mosques, temples, shops and offices, often on a daily basis. In some The authors would like to thank the British Council in Bahrain for their financial support, V. Brown for TD/GC/ITD and M. Gavin for HPLC analysis.