Hatvan– Fiľakovo railway is a non-electrified railway connecting Hatvan, Hungary with Fiľakovo, Slovakia. Once a major connecting railway, the line currently sees only local Regionalbahn service and local goods traffic. It is double tracked from Hatvan to Selyp, then single tracked for the remainder of the distance to Fiľakovo. It is a class 3 passenger and goods line from Hatvan to Salgótarján, then becomes a class 4 line from there to Fiľakovo. The line has utilized clock-face scheduling operation since 2008, when direct express train connecting service with Budapest ended. The Hungarian portion is designated as line 81 and the Slovakian portion is line 164.

Lőrinci is a town in Heves County, Hungary, beside of the Zagyva river. As of 2022 census, it has a population of 5352. The town located beside of the Hatvan–Fiľakovo railway line and the main road 21. The M3 motorway is 7.4 km far. The town has a railway stop and a station: Selyp in the north, Lőrinci in the middle. The Mátravidéki Erőmű station in the south have not public transport.