Interexpress services operated between 1986 and 1991 as express trains between Czechoslovakia, the German Democratic Republic (GDR), Hungary and Poland.
In the mid 1980s, the State railways of Czechoslovakia (Československé státní dráhy (ČSD)), the GDR (Deutsche Reichsbahn (DR)), Hungary (Magyar Államvasutak (MÁV)) and Poland (Polskie Koleje Państwowe (PKP)) decided to introduce the Interexpress train category for high value passenger train traffic between these four countries.
This conversion anticipated by one year the equivalent transformation of international express train traffic by the Western European rail operators, which introduced their own new EuroCity system only in 1987.
Following the political changes in central Europe in 1989/1990, there was no longer any demand for an isolated train service offering for international travellers.
Some of the IEx trains included through coaches at least occasionally; examples were the Metropol (to Vienna), and the Berolina (from Paris).