The aim of this paper is to account for the similarities and differences between Eastern Catalan and Valencian truncated hypochoristic words in the framework of Correspondence Theory (McCarthy & Prince 1995), specifically Transderivational Relation Theory or output-to-output correspondence relation (Benua 1995, 1997). The prosodic constituent determined by lexical stress in Catalan makes up the most of the hypochoristic truncated forms in both dialects. Faithfulness to the base in Eastern Catalan can make longer forms than the left edge of the metrical constituent imposes; instead unmarked conditions on the shape of Valencian truncated forms can force the insertion of the gender vowel, thus increasing the metrical constituent at its right edge. In addition, some Catalan hypochoristics furnish empirical evidence for the full model of Correspondence Theory since they require underlying information of the base form.