Six observation scales for measuring the skills of teachers and 1 scale for measuring student engagement, assessed in South Korea and The Netherlands, are sufficiently reliable and offer sufficient predictive value for student engagement. A multigroup confirmatory factor analysis shows that the factor loadings and intercepts of the scales are the same, within acceptable boundaries, in both countries. Therefore, we can compare the average scores of teachers in both countries in a reliable and valid way. The 289 Dutch teachers score significantly better on “creating a safe and stimulating learning climate” and “intensive and activating teaching” and almost significantly on “efficient classroom management”. We find no significant differences in “clear and structured instruction”. The 375 South Korean teachers perform significantly better than the Dutch teachers on “teaching learning strategies” and almost significantly on “differentiating instruction”. Furthermore, we find better student engagement in South Korea.