This document is Ezekiel Peeta-Imoudu's final year project which tests the validity of the Capital Asset Pricing Model (CAPM) using volatility on the London Stock Exchange from 2001-2010. The project provides a literature review on the CAPM theory and debates around its validity. It then empirically estimates beta for 12 selected companies using statistical tests like paired sample t-test, regression analysis, Pearson correlation and Kruskal-Wallis test. The results show that 11 of the 12 companies have no significant difference between estimated and actual beta, providing evidence that the CAPM is valid on the LSE.