Purpose The purpose of this paper is to explore uncertainty inherent in emotion recognition technologies and the consequences resulting from that phenomenon. Design/methodology/approach The paper is a general overview of the concept; however, it is based on a meta-analysis of multiple experimental and observational studies performed over the past couple of years. Findings The main finding of the paper might be summarized as follows: there is uncertainty inherent in emotion recognition technologies, and the phenomenon is not expressed enough, not addressed (...) enough and unknown by the users of the technology. Practical implications Practical implications of the study are formulated as postulates for the developers, users and researchers dealing with the technologies of automatic emotion recognition. Social implications As technologies that recognize emotions are becoming more and more common, and perhaps more decisions influencing people lives are to come in the next decades, the trustworthiness of the technology is important from a scientific, practical and ethical point of view. Originality/value Studying uncertainty of emotion recognition technologies is a novel approach and is not explored from such a broad perspective before. (shrink)