The lack of studies and tools that analyze the perception that grandparents have of their emotional competence towards their grandchildren, makes it necessary to design and then validate an instrument that provides information about it. To this end, a sample composed of 140 male grandparents and 210grandmothers who take care of their grandchildren took part in the study. In the validation of the scale two subsamples were considered, performing with one of them an exploratory factor analysis and with the other one a confirmatory factor analysis. As a result, a 10 item scale was obtained, distributed in four factors that explain 45.25% of the variance, with adequate reliability indexes: stress, assertiveness, difficulties to conciliate the care of grandchildren with personal time and emotional self-regulation. The scale presents acceptable concurrent validity values with perceived satisfaction and efficacy in the development of educational functions. The study also explores differential results of emotional competencies of grandparents based on gender, age and kinship.