The buildings of ashlar masonry with ashlar edging had almost identical ground plans and elevations. They feature a two-story, gabled main building with a clock tower and a one-story, eave side wing. After the nationalization of the private railroads in the 1880s, the Plettenberg reception building had been extended into a symmetrical complex by a second, mirror-image side wing around 1904 during the time of the Royal Prussian State Railways. As part of a modernization in the 1960s, the clock on the clock tower was removed and the building was given a side extension and a continuous concrete canopy across the entire front facing the station forecourt, which had a lasting impact on the building's appearance.
After the Deutsche Bahn discontinued its use of the building, the city of Plettenberg acquired it and had it completely renovated at the beginning of the 21st century, taking into account aspects of monument protection (justification of monument value/notification of entry in the list of monuments of 23.07.1991). In the process, the canopy was removed and the facades were largely restored to their original condition. The Ruhr-Sieg line itself was initially only single-tracked, although the route for a second track had been prepared with foresight. The freight volume developed so positively that this second track was laid as early as 1871. The positive development continued in the following period - apart from economic fluctuations - and meant that the track and ancillary facilities had to be expanded further and further. The connection of the Plettenberger Kleinbahn (1896) and the construction of the branch line to Herscheid (1915) also contributed to this at Plettenberg station. For decades, the station was also a locomotive depot, where one or two steam locomotives were stationed for shunting operations and for serving the Herscheid line. Locomotives of the Reichsbahn classes 74, 93 and 55 were used.
A water tower necessary to supply the locomotives was located on the opposite side of the reception building near the freight shed. The required Lokschuppen was located next to the reception building behind the platform in the direction of Hagen. In addition to these enlargements of the station and track facilities, a then modern riding signal box was built in 1932, which was, however, demolished at the end of 2006 in the course of modernization in recent years - despite its monument status. Unfortunately, the brisk industrial activity also meant that the railroad facilities increasingly became the target of air raids in the last years of World War II, which also led to bomb damage in the vicinity of the station with deaths and injuries. The most momentous attack took place on March 25, 1945, when a fully loaded passenger train of the Deutsche Reichsbahn was hit. This resulted in the deaths of 13 people and 60 others were injured, some of them seriously. Despite a large number of war damages, operations were quickly resumed.
In the context of the rationalization of the last time among other things by the shutdown and the dismantling of the Herscheid railroad, the abandonment of the general cargo and single wagon traffic also the environment changed considerably. Thus, the freight shed, which in its core still consists of the building from 1861, has been abandoned and the corresponding track systems have been shut down or dismantled. For passenger traffic, the platform facilities were modernized in 2009/10 (action program "100 stations in NRW") and the pedestrian tunnel was renewed so that today there is barrier-free access to all platforms. The station forecourt was also redesigned as part of this project. In passenger traffic, the station is now served in both directions at hourly intervals by Regional Express Line 16 "Ruhr-Sieg-Express" and Regional Train 91 "Ruhr-Sieg-Bahn" on the Essen-Hagen-Siegen route, both of which were operated by Abellio NRW until the end of 2007 and have now been taken over by DB Regio since the beginning of 2022.