The 4th International Workshop on Adaptive Optics for Industry and Me- cine took place in Munster, Germany, from October 19 to October 24, 2003. The series of International Workshops on Adaptive Optics for Industry and Medicine beganwiththe?rstworkshopinShatura/Russiain1997,thesecond workshop took place in Durham/England in 1999, and the third workshop was held in Albuquerque/USA in 2001. The workshop series started out as a true grassroots movement and kept an informal spirit throughout all four workshops. Many personal friendships and scienti?c collaborations have been formed at these meetings. This fourth workshop was supposed to be held in Beijing, China. H- ever, the program committee decided in May 2003 to move the workshop to Munster due the general perception that the SARS (Severe Acute R- piratory Syndrome) cases reported in China could lead to a large epidemic. Despite this rather short notice the workshop in Munster was attended by about 70 people. Incidentally, the workshop coincided with the 50th anniv- sary of adaptive optics, because it was October 1953 when Horace Babcock published his famous paper The possibilities of compensating astronomical seeing in the Publications of the Astronomical Society of the Paci?c.