Participation has been a relevant issue in public administration research and theory for several decades, especially in old democracies. However, recent processes of globalization, Europeanization and digitalisation, coupled with diminishing citizens’ trust in public institutions, have again made the concept of public participation topical. The aim of this paper is to provide a theoretical reflection on the concept and substance of participation in public administration and on research efforts. In order to do so, administrative participation is first defined and distinguished from other types of participation in modern democracies (political and civil participation). Participation in public administration encompasses the processes through which the public is directly involved in regulative and implementation functions of administrative organizations, as well as in the oversight of their functioning. The three main categories of participation in public administration are elaborated – regulative, implementing and oversight participation – together with some apparent forms (instruments) within each category. The main principles upon which administrative participation is based are also explained – transparency, openness, responsiveness and trust. The final part of the paper contains an overview of the existing research and evaluation of participation in public administration. The twofold value of participation – intrinsic and instrumental – is explained, its potential benefits and shortcomings are listed, and a distinction between the process and outcome dimension of participation is elaborated. Although the literature has become rather extensive and refined, one can conclude that unambiguous findings on the practical effects of participation are still deficient, especially with regard to its dependence on different contextual – especially organizational – variables.; Participacija je desetljećima važna tema teorijskih rasprava i istraživanja u javnoj upravi, naročito u starim demokracijama, ali i izvan tog kruga. Suvremeni procesi globalizacije, europeizacije i digitalizacije, zajedno sa slabim povjerenjem građana u institucije javne vlasti učinili su participaciju još aktualnijom. Cilj rada je teorijski ponovno razmotriti koncept i sadržaj participacije u javnoj upravi, kao i postojeća istraživanja participacije. Upravna se participacija najprije odvaja od drugih oblika participacije u modernim demokracijama (političke i građanske). Participacija u javnoj upravi obuhvaća procese izravnog uključivanja zainteresirane javnosti u regulativnu i provedbenu funkciju upravnih organizacija te u nadzor nad njihovim funkcioniranjem. Razlikuju se i razmatraju tri vrste upravne participacije – regulativna, provedbena i nadzorna, zajedno s njihovim pojavnim oblicima, tj. instrumentima. Glavna načela upravne participacije su transparentnost, otvorenost, odazivnost i povjerenje. Temeljem pregleda istraživanja i evaluacije upravne participacije razmatra se njezina dvostrana vrijednosna priroda, intrinzična i instrumentalna, navode se njezine prednosti i nedostaci te se utvrđuju razlike između procesne i izlazne dimenzije participacije. Unatoč brojnim i kvalitetnim istraživanjima, učinci participacije još nisu sasvim razjašnjeni, upućujući na njihovu ovisnost o različitim kontekstualnim, naročito organizacijskim, čimbenicima. Temeljem toga se, na kraju, zaključuje o više konceptualnih i metodoloških pitanja za buduća istraživanja.