In this article we investigate suffix combinations in second- and third-grade diminutive nouns in Polish and Bulgarian. We show that the formation of double and multiple diminutives in both languages is subject to phonological, morphological, semantic and psycholinguistic constraints. Although diminutive suffixes constitute a semantically homogeneous set, they do not combine freely with each other and of all possible combinations of diminutive suffixes in a language only very few exist. Both languages under scrutiny in this paper ‘filter’ their relatively large sets of DIM1 suffixes and use very few of them for the formation of DIM2 nouns, and Bulgarian also for DIM3 nouns. Moreover, only suffixes that occur in DIM2 nouns can derive DIM3 no...