Dispositional Mindfulness (DM) is the awareness of the thoughts and feelings in the present moment. DM in children and adolescents has been related to mechanisms of change in mindfulness-based interventions, which have shown significant mediation relationships with mental health outcomes (for instance, lower social anxiety, depression symptoms, or perceived stress). However, the assessment of DM among children and adolescents is being unsatisfactory due cultural biases and/or reliability issues. In this study, we examined the psychometric properties of the Spanish version of the Child and Adolescent Mindfulness Measure (CAMM) in a sample of 687 children and adolescents between 8 and 16 years old. Although the CAMM has been validated in English, Portuguese, Italian, and Catalonian versions, until now no data has been reported in a Spanish context. Results showed that the best CAMM factor structure was constituted by five items from the original version (1, 4, 7, 8, and 9). These items defined dispositional mindfulness. The rest of the items (2, 3, 5, 6, and 10) were eliminated from the Spanish final version. The analyses revealed good reliability and internal consistency for the Spanish version of the CAMM. As we expected, the confirmatory factor analysis showed the unidimensional structure of the CAMM.