This book constitutes the refereed proceedings of the 24th European Conference on Object-Oriented Programming, ECOOP 2010, held in Maribor, Slovenia, in June 2010. The 24 revised full papers, presented together with one extended abstract were carefully reviewed and selected from a total of 108 submissions. The papers cover topics such as programming environments and tools, theoretical foundations of programming languages, formal methods, concurrency models in Java, empirical methods, type systems, language design and implementation, concurrency abstractions and experiences.