This article examines the stability of Norwegian prospective preschool teachers' enjoyment of mathematics and their mathematics-related self-efficacy before, during, and after a teacher-education examination. In addition, the stability of the two constructs across countries was examined through a comparison with Germany. The data revealed partial stability (technically speaking, metric invariance) of enjoyment but not of self-efficacy. Self-efficacy increased significantly before and after the examination without decreasing enjoyment, which may be a result of increased learning time. Prior mathematical knowledge predicted the level and development of enjoyment and self-efficacy in both countries. Many Norwegian students reported low mathematics-related enjoyment and self-efficacy, including negative developments. It may be important to provide positive experiences of mathematical activities during preschool teacher education.