This study addresses the complexity of academic writing, highlighting the lack of attention to the assessment of writing. The aim is to develop and empirically validate an analytical rubric for assessing the quality of academic essays. The research design included construct definition, expert validation and application to 67 essays of first-year university students. The results show the validity and reliability of the instrument, suggesting its usefulness for the assessment of argumentative essays in academic settings. This approach provides a valuable tool for the academic community seeking to improve the assessment of writing in university contexts.