In line with self-determination theory (SDT: Deci & Ryan, 1985, 2002) the satisfaction of the basic psychological needs for autonomy, competence, and relatedness has been identified as an important predictor of behavior and optimal functioning in various contexts including exercise. The lack of a valid and reliable instrument to assess the extent to which these needs are fulfilled among Portuguese exercise participants limits the evaluation of causal links proposed by SDT in the Portuguese exercise context. The aim of the present study was to translate into Portuguese and validate the Basic Psychological Needs in Exercise Scale (BPNES: Vlachopoulos & Michailidou, 2006). Using data from 522 exercise participants the findings provided evidence of strong internal consistency of the translated BPNES subscales while confirmatory factor analysis supported a good fit of the correlated 3-factor model to the data. The present findings support the use of the translated into Portuguese BPNES to assess the extent of basic psychological need fulfilment among Portuguese exercise participants.