While much work has been done on the description of the mass/count distinction in different geographical areas, Brazilian Indigenous languages are still highly underrepresented in the field. This paper presents the results of a project that involved researchers describing the mass/count distinction in 15 Brazilian Indigenous languages, based on a questionnaire we prepared in 2016 in order to explore the distribution of bare nouns, plurals, numerals, and quantifiers (see Appendix). Three main observations will be drawn. First, number marking and countability are independent. Second, counting is not restricted to natural atoms. Third, since there seems to be no systematic symmetry in the distribution of plurals, numerals, and quantifiers, we argue that the standard diagnostics for countable vs. non-countable nouns are highly language-specific.