Abstract This study aims to perform cross-cultural adaptation and validation of the “Self-efficacy scale to brush teeth at night” with a Brazilian adult population. Translation and cross-cultural adaptation to the Brazilian-Portuguese language were done according to the stages recommended in the literature. Construct validity was carried out by mean of exploratory and confirmatory factorial analysis in a sample of 198 adult subjects. The reliability of the instrument was measured by Alpha and Omega indices. The model was observed to have been established as one-dimensional for all indicators, with explained variance of 85.7%; factorial loads between 0.85 and 0.91; and with communalities between 0.72 and 0.83. The goodness of fit of the model shown by the confirmatory model were between 0.98 and 0.99; with factorial loads between 0.85 and 0.93, and regression values between 0.69 and 0.84, all above the minimum indices established for instrument quality. For reliability, the Alpha and Omega values had identical indices of 0.95 showing high levels of reliability of the model. The G-H index replicability was 0.96, indicating the stability of solution in other contexts and samples. We concluded that all indicators represented excellent evidence of scale validity to measure self-efficacy to brush teeth at night.