Introduction: The assessment of student motivation can be a powerful tool for understanding the factors that can influence the school environment, where students, families, teachers, psychologists or administration can develop interventions related to the improvement of learning through the motivational style based on the Self-Determination Theory (SDT). The present study aims to offer a Spanish version of the Academic Self-Regulation Questionnaire (SRQA), one of the most widely used instruments worldwide to measure academic motivation. Method: A confirmatory factor analysis (CFA) was conducted on a sample of 1343 elementary school students aged 8 to 13 years. To analyse the divergent validity, a correlation analysis was carried out between the four-factor model of the SRQ-A and to analyse its reliability, Cronbach's alpha and McDonald's omega were used. Also, its invariance was tested taking gender and grade as reference. Finally, in order to analyse its convergent validity, a Pearson correlation of the motivational regulatory styles with the level of satisfaction of basic psychological needs was carried out. Results: A good convergent and discriminant validity of the reduced Spanish version of the SRQ-A was shown, as a positive correlation was observed between the most self-determined styles and the level of satisfaction of autonomy, competence and relatedness needs. A multiple-group CFA showed that the structure of the four-factor model did not vary according to gender or grade level. Discussion or Conclusion: The Spanish version of the SRQ-A demonstrates that it is a reliable instrument for measuring academic motivation described in the TAD in elementary school students.