The current concept of inclusive education brings to light the need for assessment of pre-service and in-service teachers' attitudes towards inclusion, as they are essential agents to achieve full educational inclusion. The present study aimed to adapt a simple unidimensional tool to assess attitudes towards inclusion, the TAI scale. A total of 320 students of the BSc in Teacher Education and 89 in-service teachers took part in this study. The final adapted version of the scale (TAIS-SP) showed adequate psychometric properties.