This study examines the relationship between social background factors and educational achievements. It draws on unique data from London LEAs. The paper illustrates detail analysis on levels of disadvantage in schools and the complexities of judging school performance including discussion on the potential of z-score indicators to measure the levels of deprivation in urban area schools. Overall, the findings from the empirical evidence suggests that there is a strong relationship between disadvantage and examination success, with LEAs located in non-deprived areas (...) tending to obtain higher percentages 5 + A*-C good GCSE passes. Further analysis of the relationship between pupils background and school achievement also confirmed, by and large, that schools with a higher number of disadvantaged families do less well than schools where, a small proportion of their pupils come from disadvantaged families. The paper concluded that uncontextualised performance table is fundamentally flawed and argued for the need to compare like with like and move beyond league table approaches of comparing schools. Policy implications are highlighted as well as practical suggestions. (shrink)