Across West Europe, we observe increasing fragmentation of party systems. Formerly major parties loose support, while green and radical right parties enter and become electorally more successful. How does this affect policy representation? On the one side, a diverse set of political parties offering distinct standpoints potentially diminishes the distance between voters and their representatives in parliaments. However, fragmentation might also have negative effects on policy representation. If fragmentation goes in hand with coalition governments located off the centre of the voter distribution, government representation diminishes with increasing fragmentation. Also, the number of potential coalitions increases when the effective number of parties increases. This can have negative effects on accountability, as the link between changes in the vote shares and changes in government composition is weakened. Applying multilevel regression models to survey data for Western Europe, this paper investigates the effects of fragmentation on policy representation and on accountability.