This paper develops and validates an instrument to assess Teaching Competency in Physical Education, specifically while performing sessions of motor skills and body language games with children. A literature review highlights the great value of such competency and of implementing these activities in Physical Education during early childhood. The benefits of using rubrics in this field are also discussed. Following the curricular guidelines of the application context, the first version of the Teaching Competency while performing Motor Skills and Body Language Games Rubric (TC/MSBLG-R) was proposed. Elements of the instrument were reviewed critically by using expert judgement (n = 6) to ensure the high quality, relevance, and comprehensibility of the TC/MSBLG-R items and correct feature association. The excellent results obtained from the pilot test (n = 333) reinforced the curricular foundations, and the validity and reliability of the rubric was proved (Cronbach's alpha = .955). An Exploratory Factor Analysis proposed a set of categories consistent with the initial approach, and a Confirmatory Factor Analysis showed acceptable relationships among the rubric categories and items. The fit indices suggested that the data fit adequately to the default model (χ2/df = 2.901, Root Mean square Residual = .06; Root Mean Square Error of Approximation = .076), and a Pearson's correlation test verified that there were positive significant correlations among the proposed categories. Therefore, the rubric has shown good results in this validation process and carries the potential to promote Teaching Competency while implementing sessions of motor skills and body language games in many ways and contexts.