Abstract Parliamentary debates represent an essential part of democratic discourse and provide insights into various socio-demographic and linguistic phenomena - parliamentary corpora, which contain transcripts of parliamentary debates and extensive metadata, are an important resource for parliamentary discourse analysis and other research areas. This paper presents the Slovenian parliamentary corpus siParl, the latest version of which contains transcripts of plenary sessions and other legislative bodies of the Assembly of the Republic of Slovenia from 1990 to 2022, comprising more than 1 million speeches and 210 million words. We outline the development history of the corpus and also mention other initiatives that have been influenced by siParl (such as the Parla-CLARIN encoding and the ParlaMint corpora of European parliaments), present the corpus creation process, ranging from the initial data collection to the structural development and encoding of the corpus, and given the growing influence of the ParlaMint corpora, compare siParl with the Slovenian ParlaMint-SI corpus. Finally, we discuss updates for the next version as well as the long-term development and enrichment of the siParl corpus.