Morning or Evening person? Which type are you? Self-assessment of chronotype

•Hypothesis that people can self-assess chronotype though a single item is tested.•The Portuguese version of the rMEQ shows high reliability.•The self-assessment item provides reliable information distinguishing chronotypes.

A marked individual difference is the morningness–eveningness preference or chronotype. Presenting its high relevance in predicting human behavior, we stress the need to control for this dimension in different studies, suggesting that this can be easily and succinctly done since individuals are aware of their chronotypes. We tested this hypothesis selecting the self-assessment item from the rMEQ scale, demonstrating that the item by itself is capable of classifying individuals in the same category as the score obtained through the original scale.