On behalf of the program and the local organizing committees, I would like to invite you to participate in the 2nd International Workshop on Klinefelter Syndrome, which will take place in Münster, Germany, from March 10 to 12, 2016. In 2010, the first International Workshop on Klinefelter Syndrome was held in Copenhagen with great success. Over the past few years, our knowledge of Klinefelter Syndrome has significantly improved. The newly discovered clinical phenotypes suggest that the presence of a supernumerary chromosome leads to a multifactorial disease, in which hypogonadism is only one facet among others. In view of the steadily emerging fields of clinical and scientific research on Klinefelter Syndrome, we have decided to organize the 2nd International Workshop in Münster. We we have compiled a program that will cover the different aspects of Klinefelter Syndrome ranging from X inactivation to neuropsychological effects. Renowned experts have been invited to speak at the workshop, but the 2-day event will also give young scientists and clinicians an opportunity to present their recent work during an oral communication and poster session. The workshop will be held at the Germania campus, a former brewery, harboring a hotel, restaurants and pubs all within easy reach from the conference venue, which will further stimulate exchange and discussion among the participants. We are looking forward to welcoming you to this unique event to be held in Münster in March 2016. Jörg Gromoll