The Lexicon of Architects, a part of the “Atlas of 20th Century Croatian Architecture”, is an open book: a project gradually expanding, growing, being supplemented, re-edited, translated, as well as involving a wider scope of media in its presentation. This Lexicon is a sort of gist of established methodological approach of the “Atlas of 20th Century Croatian Architecture”, in which the phenomenon of Croatian architecture is being registered in its basic stage and viewed through the prism of authorial architectural approach. In this regard, this book is perceived not only as a resume of past times but also as an initial reference of development of Croatian cultural space. This edition portrays sixty one architects presented in standard alphabetical order. They have been selected from the generation of architects active during the 20th century, born until 1930. In this way, a relevant scope of architectural production from the beginning of the 20th century up to the 1960’s has been covered. Using selection criteria adapted to the Faculty of Architecture syllabus, the architects were chosen primarily as a reminder for its students, while next issues will supplement the analyzed period but also gradually expand the age limit to those architects active in the 19th century as well as to those nearer to the present time. Relevant contributions on every author are uniform, consisting of an “authorial sheet” i.e. four pages. The introductory page places the author in the chronological framework of Croatian architects. In this issue, they are presented within a wider choice of authors, as a hint of future issues of the Lexicon. This list is supplemented by the list of architects, theoreticians and journalist who had, by their writings, created the framework of architectural discipline in Croatia. The following page presents facts on the life and work of the relevant author. They include essential biographical facts on the architect’s schooling, his/her belonging to a certain circle, and influence on the next generations. The choice of works is reduced to the most important ones ; selected buildings belong in the first place to the representative examples of 20th century Croatian architecture, and only secondly they elaborate an author’s architectural oeuvre. Special care has been taken to exact dating, as well as to the exact location of a relevant building, in order to make these facts of use in an eventual tour of buildings as well as in creating one’s personal architectural guide. The last two pages bring eight illustrations, which not always illustrate the textual choice of works. Instead, on the basis of anthological criteria, they try to illustrate the characteristic authorial expression of the architect in question. The page layout is taken over from the digital presentation media, while the material found in this book is the one of the relevant teaching courses. In fact, it’s scope and reproduction is brought here in the same way and content as it is presented in the digitalized course materials of all study grades at the Faculty of Architecture of the University of Zagreb. The book ends with a registry of architects born until 1960, with their exact position in the “Atlas”. The list is based on the alphabetical and chronological criteria defined by the author’s date of birth. The list includes all the architects with their projects and buildings present in Croatia, as well as those Croatian architects who were active in other countries. Architects presented in this lexicon are: Alfred Albini, Vlado Antolić, Bela Auer, Franjo Bahovec, Helen Baldasar, Aladar Baranyai, Vjekoslav Bastl, Hinko Bauer, Miroslav Begović, Bernardo Bernardi, Zdravko Bregovac, Emil Ciciliani, Frane Cota, Andrija Čičin-Šain, Julije De Luca, Juraj Denzler, Nikola Dobrović, Aleksandar Dragomanović, Zoja Dumengjić, Hugo Ehrlich, Igor Emili, Stanko Fabris, Ignjat Fischer, Drago Galić, Marijan Haberle, Lavoslav Horvat, Drago Ibler, Mladen Kauzlarić, Josip Kodl, Viktor Kovačić, Slavko Löwy, Rudolf Lubynski, Boris Magaš, Juraj Neidhardt, Zlatko Neumann, Radovan Nikšić, Kazimir Ostrogović, Lovro Perković, Bogdan Petrović, Josip Pičman, Stjepan Planić, Vladimir Potočnjak, Zvonimir Požgaj, Ivo Radić, Božidar Rašica, Vjenceslav Richter, Josip Seissel, Egon Steinmann, Zdenko Strižić, Neven Šegvić, Edo Šen, Nada Šilović, Vladimir Šterk, Vladimir Turina, Antun Ulrich, Dinko Vesanović, Ivan Vitić, Mladen Vodička, Zvonimir Vrkljan, Ernest Weissmann and Ivan Zemljak.