Public participation GIS (PPGIS) approaches, often online participatory mapping, are used as participatory tools in land use planning. Applying PPGIS is expected to create data that contribute to decision-making processes in different organizations. The challenge with the use of PPGIS is that information often remains at the level of data collection without deeper and concrete use of the data. However, further research is required to better assess the impact of PPGIS approaches in actual land use-related decision-making. The essential questions are how PPGIS data have been used in decision-making, and how the application of the PPGIS approach is beneficial for land use planning processes. We aim to address these questions through three cases in Finnish Lapland, a sparsely populated region with mainly publicly owned land. The analysis is performed from the perspective of the organizations that applied PPGIS surveys. The results show that PPGIS can improve interaction between organizations and respondents in land use planning. PPGIS is particularly beneficial in the early phases of a land use planning process. In addition, for the most beneficial impact we advise using PPGIS to manage practical land use planning-related issues and to store collected data systematically. © 2023

Decision-making; Impact of participation; Impact research; Land use planning; Participatory mapping; PPGIS