This chapter reviews the epidemiological evidence regarding potential health effects of exposure to radio frequency (RF) fields below current guidelines that cannot cause substantial heating of tissue. The scientifically established mechanism for interaction between RF fields and the human body is heating, and current exposure guidelines are set to protect from excessive heating of tissue. The general population is exposed to different sources of RF fields, but most common in the everyday environment are wireless communication applications such as mobile and cordless phones, broadcasting, or WLAN/WIFI. Risk of neurodegenerative disease was studied in relation to extremely low-frequency electric and magnetic fields, mainly at the workplace, but much less often for RF fields. Long-term consequences of RF fields on health related quality of life needs to be investigated by observational epidemiological studies. Mobile phone use is an important source of localized RF exposure to the head when the phone is held to the ear.