The knee is one of the most complex joints in human body and is often exposed to injuries. There are various causes of pain in the knee.The most common ones are: inflammatory processes, degenerative processes, injuries and static deformities. In establishing diagnosis, it is important to take patient’s history and carry out orthopaedic examination to assess the general condition of the joint,intensity of pain and extent of movements. This is followed by ultrasound, X-ray, arthroscopy and magnetic resonance which is most useful.