Most common fishway types in Finland are pool and weir and vertical slot fishways. Recently, Denil fishways have been built, too. Most of the fishways are located inland and they are for both salmonids and freshwater species. Fishways have been studied at the University of Oulu, Finland since the early 1980s. The promoter has been Hydraulic and Water Resources Engineering Laboratory, which as organized the research in cooperation with the Department of Zoology, the Department of Biophysics, and the Oulu Institute of Technology. Subtopics of the fishway research have been fish swimming behavior and fishway hydraulics. During the research, the main terms of fish behavior and physiology to fishways and fishway design have been determined. Fishway structures that hydraulically meet these terms have been constructed according to the results of these studies. This paper presents the fishway research done at the University of Oulu, and discusses future trends and needs in research in improving fish migration and reproduction possibilities. The results of the fishway studies have been used in optimizing the hydraulic conditions of fishways and in designing of fishways. Some case studies are reported, too.