The paper presents the current state of knowledge on the Romanian Dendrocoelidae as part of the European/Palearctic Dendrocoelidae, with emphasis on the contribution of the Romanian zoologists Radu Codreanu and Doina Balcesco. The main objective of the work was to find the gaps in knowledge for future alignment with current standards. The topics of the article include: the species inventory; a short historical perspective over the classical phylogenetic system with an overview of the morphological characters used in the systematic of the group. The study analyses the arguments (and hypotheses) brought by Codreanu, Balcesco and other authors regarding the phylogenetic value of some characters: a) the position of the oviducts between the male atrium and the bursal canal (typical for Paradendrocoelum); b) the eyes and the penial flagellum in relation with the palaeogeographical context governed by the Quaternary Glaciation; c) the point of view of Codreanu and Balcesco on the origin and composition of the actual Romanian Dendrocoelidae fauna. The major key finding is that the Dendrocoelidae species on the Romanian territory should be reinvestigated in an integrative way. Specific future research needs, and future directions of study are suggested.