Research into motivation in education mainly centres on students' learning motivation. This article reports on an interview study of teacher motivation with the aim of investigating the effects of student-related factors and tutors' personal factors on the motivation of language tutors in the distance learning context. Findings from the study indicate that external sources of influence include students' engagement in learning English, motivation to learn English, progress made, foundation in English and appreciation of tutors' teaching, while tutors' internal factors are their self-efficacy in teaching, reflection and self-initiated professional development, interest in the profession of teaching English as well as their sense of achievement. Analysis of the data also suggests that more concrete measures are needed to counteract the demotivating effects from these two dimensions. Implications and suggestions are discussed with regard to enhancing tutor motivation more effectively.