Computer Science (CS) is a new subject area for many K-12 teachers around the world, requiring new disciplinary knowledge and skills. Teacher social-behavioral factors (e.g. self-esteem) have been found to impact learning and teaching, and a key part of CS curriculum implementation will need to ensure teachers feel confident to deliver CS. However, studies about CS teacher self-esteem are lacking. This paper presents an analysis of publicly available data (n=219) from a pilot study using a Teacher CS Self-Esteem scale. Analysis revealed significant differences, including 1) females reported significantly lower CS self-esteem than males, 2) primary teachers reported lower levels of CS self-esteem than secondary teachers, 3) those with no CS teaching experience reported significantly lower CS self-esteem, 4) teachers with 0-3 years experience had a negative CS self-esteem, but after four years, teachers had a positive CS self-esteem, and 5) teachers who lived further from metropolitan areas and in some countries reported lower CS self-esteem. These initial findings suggest a pressing need for future research to look further into teacher CS self-esteem to inform teacher CS professional development.