The purpose of this convergent mixed-methods study was to evaluate the effect of educational robotics on pre-service teachers' programming comprehension and motivation. Computer science is increasingly being integrated into K-8 curricula. However, a shortage of teachers trained to teach basic computer science concepts remains unresolved. This study thus utilized educational robotics as "mindtools" to teach programming concepts to pre-service teachers. Data were obtained through a pre-post comprehension assessment, a pre-post motivation survey, field notes, and individual interviews. The findings of this study indicated that pre-service teachers' comprehension of programming concepts and motivation related to programming can be improved through educational robotics to statistically significant levels. Design implications on integrating educational robotics into pre-service teacher programming instruction are discussed.