Following the successful WCET Tool Challenges in 2006 and 2008, the third event in this series was organized in 2011, again with support from the ARTIST DESIGN Network of Excellence. Following the practice established in the previous Challenges, the WCET Tool Challenge 2011 (WCC'11) dened two kinds of problems to be solved by the Challenge participants with their tools, WCET problems, which ask for bounds on the execution time, and ow-analysis problems, which ask for bounds on the number of times certain parts of the code can be executed. The benchmarks to be used in WCC'11 were debie1, PapaBench, and an industrial-strength application from the automotive domain provided by Daimler AG. Two default execution platforms were suggested to the participants, the ARM7 as \simple target" and the MPC5553/5554 as a \complex target," but participants were free to use other platforms as well. Ten tools participated in WCC'11: aiT, Astree, Bound-T, FORTAS, METAMOC, OTAWA, SWEET, TimeWeaver, TuBound and WCA.