Purpose The purpose of this study is to characterize output and impact evaluation initiatives from the perspective of entrepreneurs and investors of social enterprises (SE) by highlighting their relevance, implementation processes and consequences. Design/methodology/approach This study adopted a qualitative approach through a multiple case study. This study also analyzed ten SE in five areas and three investors, using semi-structured interviews, codification and content analysis. Findings Evaluation is still at an initial stage in these businesses, and there is a gap between what the field-specific literature proposes and what firms do. Although entrepreneurs feel that evaluation is essential to demonstrate their value and confirm their purpose and impact, it is not a priority. Research limitations/implications Due to the small number of Brazilian enterprises and investors, it is impossible to generalize the results. Practical implications The results are relevant to rethink strategies, processes and methodological tools that seek to portray, more realistically and reliably, the evaluation dimensions in SE. Social implications This study highlights the risk regarding the legitimacy of social impact ventures since, without the due causal inferences, it is not easy to prove the impact they claim to achieve. This situation conducts to the weakening of the ecosystem leading to the emptying of the term impact. Originality/value The main research contributions address the methodologies, practices and evaluation routines of some Brazilian SE and their investors, presenting the characteristics, perceptions and limitations of the studied ventures.