AbstractThis issue of physica status solidi (b) contains the Proceedings of the 12th International Conference on High Pressure Semiconductor Physics (HPSP‐12) which took place in Barcelona, Spain, on 31 July– 3 August 2006. The meeting was held at the CosmoCaixa Museum (see also the Conference Report and Concluding Remarks by M. Cardona at the end of this issue [1]). HPSP‐12 was a satellite conference to the 28th International Conference on the Physics of Semiconductors held in Vienna, Austria, 24–28 July 2006. Around 125 scientists were registered at HPSP‐12, and 89 papers were submitted to the Proceedings. These describe recent research on various physical properties under pressure like optical absorption, vibrational states, structural transformations, transport properties, electronic structures, superconductivity, among others. The materials and solid state systems examined include bulk, crystalline materials of various compositions, alloys (diluted nitrides), quantum‐well structures, quantum dots, fullerenes and carbon nanotubes, microrods, devices like lasers, etc. Interesting results were presented in several experimental papers as well as in accounts of theoretical work.HPSP‐12 was supported financially by the Spanish Ministry of Education and Science (MEC), Obra Social Fundació “la Caixa”, Fundación BBVA, Consejo Superior de Investigaciones Científicas (CSIC), m.t. Brandão España s.l., Generalitat Valenciana, Carburos Metálicos S.A., Universitat de València, and Universidad de La Laguna.We are very grateful to the local organizers and thank the Program and International Advisory Committees. Not least, we thank the many reviewers who submitted their detailed referee reports within short notice.The agreement with the publishers Wiley‐VCH on the publication of the proceedings of the HPSP conferences is very important, in particular because the papers are reviewed as for a usual international journal. This ensures a high standard of the accepted papers. However, the quality of the research presented is closely related to how the HPSP community itself defines the scope of its meetings. One might ask, whether the subjects, which in the past have been very successful in defining the programs of the HPSP conferences, could in part be exchanged with new fields in order to adjust more to new developments in condensed matter research. The next HPSP conference, number 13, will be held in Fortaleza, Brazil, 21–28 July 2008. This gives time for all of us to suggest new directions and offer assistance to the organizers (Chair: Prof. V. Lemos).September 2006