The paper deals with adult education in Slovenia in individual periods from the end of the 18th to the 21st century. The research method is historical analysis. The purpose of the qualitative research is to show how the institutional and mass education of adults developed in individual periods, how society influenced adult education, and the development of andragogical ideas and andragogy. The most important institutions, their purpose, the mass education of adults, and individuals who introduced new andragogical ideas and efforts to develop andragogy are presented. We found that the development of adult education was different over time, depending on the development of society, economy, and politics. Andragogical ideas were in evidence at the end of the 18th and in the 19th century. The theory of adult education originated at the beginning of the 20th century. A new scientific discipline, andragogy, developed in the second half of the 20th century from social needs for new knowledge, experts and from research into the practice of adult education. The first study programme in andragogy was established at the Faculty of Arts of the University of Ljubljana. Prispevek obravnava izobraževanje odraslih na Slovenskem od konca 18. do 21. stoletja. Raziskava je zgodovinska analiza. Namen kvalitativne raziskave je prikazati, kako se je razvijalo institucionalno in množično izobraževanje odraslih po posameznih obdobjih, kakšen je bil vpliv družbe na izobraževanje odraslih ter na razvoj andragoških idej in andragogike. Predstavljeni so najpomembnejše institucije, njihov namen, množično izobraževanje odraslih, nekateri posamezniki z andragoškimi idejami in prizadevanji za razvoj andragogike. Ugotovili smo, da je bil razvoj izobraževanja odraslih po obdobjih različen, odvisen od razvoja družbe, gospodarstva in politike. Andragoške ideje zasledimo konec 18. stoletja in v 19. stoletju. V začetku 20. stoletja nastanejo prvi zametki teorije izobraževanja odraslih. V drugi polovici 20. stoletja pa se iz družbenih potreb po novih znanjih, strokovnjakih ter iz raziskovanja prakse izobraževanja odraslih razvije nova znanstvena disciplina – andragogika. Prvi študij andragogike je bil na Filozofski fakulteti Univerze v Ljubljani.