Paola Bucci Department of Psychiatry, University of Naples SUN, Naples, Italy WPA partnership with the World Health Organization in the development of the ICD-11chapter on mental disorders The development of the 11th edition of the International Classifi cation of Diseases (ICD) is ongoing, and the diagnostic system is expected to be published in the year 2015. <...> The WPA is supporting the World Health Organization (WHO) in the production of the chapter on mental disorders. <...> TheWPAPast-President, M. Maj, is a member of the International Advisory Group for the ICD10 revision and the chairperson of the Working Group on Mood and Anxiety Disorders. <...> Several WPA offi cers or experts have been appointedaschairpersonsormembers of ICD-11WorkingGroups. <...> Thechairpersons include W. Gaebel (Working Group on Psychotic Disorders), P. Tyrer (Working Group on Personality Disorders), L. Salvador-Carulla (Working Group on Intellectual Disabilities), O. Gureje (Working Group on Somatic Distress and Dissociative Disorders), and D. Stein (Working Group on Obsessive-Compulsive and Related Disorders). <...> The WPA Member Societies participated in the WPA-WHO Global Survey of Psychiatrists’ Attitudes Towards Mental Disorders Classifi cation [1]. <...> This survey collected information from 4887 psychiatrists concerning their regular use of a formal classifi cation system, the classifi cation system most used, and the number of diagnostic categories desired, and their views on the most important purposes of classifi cation, the use of strict criteria versus fl exible guidance, how to incorporate severity and functional status in a classifi cation of mental disorders, the utility of a dimensional component, the cultural applicability of current classifi cations, and the ease of use and the goodness of fi t of ICD-10 diagnostic categories. <...> The results of this survey are being used to improve the clinical utility of the ICD-11 chapter on mental disorders. <...> Several WPA Member Societies and experts are being or will be involved in ICD-11 fi eld trials and in the various translations/adaptations of the diagnostic system. <...> The WPA is actively contributing to the process of harmonization between the ICD-11 and the DSM-5. <...> Within the frame of the 15th World Congress of Psychiatry, held in Buenos Aires, Argentina in September 2011, several sessions related to the ICD-11 development took place, including a Special Symposium entitled “Developing the ICD-11 classifi cation of mental disorders: fi eld <...>