This work questions the centrality of the semantic notion of diminished size in the description of the diminutive -inho in Brazilian Portuguese. Both grammatical and descriptive traditions tend to consider the idea of small size as the most relevant aspect of the Portuguese diminutive, leaving other values and functions in a secondary position. On the basis of the analysis of diminutive occurrences on a mid size corpus of Portuguese speech, this study aims to clarify some polemic topics in the description of the diminutive in Brazilian Portuguese, focusing on the meaning and use potential of the diminutive -inho and on the relevance of semantic and pragmatic aspects of the description of diminutive formations. The research is based on theoretical contributions of Cognitive Linguistics; its empirical part draws from methodologies offered by Corpus Linguistics. The program WordSmith Tools was used in the extraction and analysis of the data. The analysis show the actual frequency of the small size meaning in Portuguese speech, as the informants of the corpus are all native Brazilian Portuguese speakers. This result is compared with the frequency of the diminutive -inho used for evaluative purposes or interactional strategies in the corpus. The general results of the corpus analysis show that the idea of diminished size occupies a peripheral position in the use of diminutive formations in Brazilian Portuguese. The data suggest that different aspects of interactional procedures are grammaticalized in the suffix -inho. The conclusion is that the pragmatic dimension of the process of diminutive formation is much more significant than has been previously acknowledged.