Magnus Hallbäck, Henrik Alfredsson, Dan Henningson and Arne Johansson organized the ``ERCOFTAC/IUTAM Summer School on Turbulence and Transition Modelling'' in June 12--16, followed by a two-days workshop (June 19--20), at KTH. The summer school week was started off by two days of tutorials on turbulence modelling and stability and transition theory, given by Alfredsson, Burden, Hallbäck, Henningson and Johansson. During the next three days lectures on large-eddy-simulation techniques, single-point turbulence modelling and transition prediction methods were given by invited researchers in the field (Dr. F. Bertolotti, Prof. J. Chasnov, Prof. B.E. Launder, Prof. U. Piomelli and Dr. T.-H. Shih). The summer school attracted one hundred and eleven (111) participants of which thirty came from 12 different foreign countries. The majority of the participants came from universities but almost one out of four came from industry or research institutes. During the workshop four different test case were studied. Reference data obtained from experiments or direct numerical simulations were compared to results obtained through use of turbulence models or other transition prediction methods. The workshop was attended by 49 researchers.