Rapid Technological development induces increase of generation of used electric and electronic equipment waste, causing a serious threat to the environment. Waste printed circuit boards (WPCBs), as the main component of the waste, are significant source of base and precious metals especially copper and gold. Printed circuit boards (PCBs) are currently being dumped in landfills or incinerated which is causing a serious environmental harm in the form of toxic gases or leached hazardous compounds. To recover these metals from waste has always been a challenge. The paper here presents a detailed literature review on the components and the metal content of PCBs.