The benefits of peer tutoring in mathematics have repeatedly been proven at different educational levels. Nevertheless, mathematics teachers' perceptions towards this methodology and whether they are adequately trained to implement the practice is information that remains uncertain. Surveys and questionnaires directed at teachers regarding peer tutoring are lacking. Determining teachers' knowledge and perceptions on this topic is important, as that knowledge and those perceptions affect their teaching practices and, therefore, student learning. This validation study was designed to evaluate questionnaire responses from mathematics teachers regarding their knowledge, perceptions and attitudes towards peer tutoring so that implications for practice and policy could be determined. A four-factor structure questionnaire was developed. Strong correlations were reported between knowledge and attitudes. Females, less experienced and public school teachers showed greater values. A conclusion is that female teachers are more sensitive than male teachers regarding students' inclusion and active learning.