An introduction to quantum Monte Carlo methods Monte Carlo methods have been very prominent in computer simulation of various systems in physics chemistry biology and materials science. This book focuses on the discussion and path integral quantum Monte Carlo methods in many body physics and provides a concise but complete introduction to the Metropolis algorithm and its applications in these two techniques. To explore the schemes in clarity several quantum many body systems are analysed and studied in detail. The book includes exercises to help digest the materials covered. It can be used as a tutorial to learn the discussion and path integral Monte Carlo or a recipe for developing new research in the readers own area. Two complete Java programs one for the discussion Monte Carlo of 4He clusters on a graphite surface and the other for the path integral Monte Carlo of cold atoms in a potential trap are ready for download and adoption.