The inclusion of students with disabilities into regular physical education classes has provided a tremendous challenge to physical educators who have strived to meet the needs of all of their students. The purpose of this study was to ascertain the relationship between physical education teachers’ attitudes toward the inclusion of children with mild and moderate mental disabilities in physical education settings and the amount of practice attempts performed and the levels of success attained by these students compared to their non-disabled peers. This research examined the independent variables of teacher attitude and type of student. The dependent variables chosen for the investigation were: (a) student practice attempts; (b) student success rates, using the individual teacher’s definition for success; and (c) student success rates, using the researcher’s definition of success with reference to the age specific mastery statistics provided in the Test of Gross Motor Development – II (Ulrich, 2000). The present study was designed using a mixed – methodology. The quantitative section involved the observation of 10 teachers with a positive attitude toward inclusion and 10 teachers with a negative attitude toward inclusion. The qualitative section involved the interviewing of two teachers with a positive attitude toward inclusion and two teachers with a negative attitude toward inclusion. The results from the quantitative phase of the study were compared and contrasted (triangulated) with the results from the qualitative phase of the study and were used to examine the effect of teacher attitude on the practice attempts and success level of children with and without disabilities in physical education classes. The findings from this mixed-method design suggested a relationship between teacher attitude toward inclusion and teacher effectiveness. Specifically, teachers with a positive attitude toward inclusion provided all of their students with significantly more practice attempts, at a significantly higher level of success. In addition there was some evidence that teachers with the more positive attitudes regarding inclusion had: (a) higher expectations for their students’ motor performance, (b) engaged in more in-depth lesson planning, (c) used more teaching styles, and (d) identified multiple focus areas or objectives. Keyword(s): adapted physical activity, elementary education, youth-at-risk