This paper explores the effects that different institutional mechanisms for legislative representation have on ethnic diversity in the lower chamber of the Romanian parliament. It uses an original data set to examine representational outcomes generated by a combination of proportional representation and reserved seats provisions. The findings highlight the benefits that Romania’s choice of electoral rules generated for smaller minority communities and limitations that these rules impose on the nature and extent of legislative representation of large minority groups. The paper provides evidence for qualifying the scholarly support in favour of proportional representation. It also draws attention to potential trade-offs between communal representation and ethnic inclusiveness of main political parties that the use of special mechanisms for minority representation might encourage.