Recent evidence suggests that constitutional judges appointed by different institutions could have a distinct approach to adjudication. We use the particular case of the Spanish Constitutional Court to empirically investigate this hypothesis. Constitutional judges in Spain have different professional backgrounds and are selected by four different institutions, namely executive, legislative (lower and upper houses), and judicial branches of government. We find some evidence that they exhibit different patterns of invalidating statues and dissenting. However, the results also show that professional backgrounds and appointing institutions do not seem to shape politicization.