Context
There is a growing interest in the fields of psychiatry and psychology to investigate the relationship between personality and psychopathology. The Big 5 is a model developed to investigate five personality dimensions: Extroversion, Amiability, Conscientiousness, Neuroticism and Openness. In the present study, we describe the process of translation and adaptation of a free tool to evaluate the Big 5 model into Brazilian Portuguese: The Big-5 Inventory (BFI). The instrument has 44 items with a Likert scale of response from 1 to 5.

Objective
To translate and adapt the BFI into Brazilian Portuguese.

Method
The adaptation was conducted in the following steps: 1) Translation 2) Evaluation Committee 3) Back-translation 4) Pilot study 5) Evaluation Committee 6) Application. The sample had 490 participants from various regions of Brazil, the age of the participants ranged from 18 to 71 years, and most of them have completed high school (62.9%) and are women (75%).

Results
A model with the following adjustment indexes was found: X²/gl: 1.954; GFI: 0.924; CFI: 920; RMSEA: 0.044.

Conclusion
The results are suggestive of a Brazilian version of this instrument and represent a free option for investigating associations with the Big-5 in psychiatry.