The Job Demands-Resources Model was used as the basis of the proposal that there are two parallel processes involved in work-related well-being among teachers, namely an energetical process (i.e., job demands --> burnout --> ill health) and a motivational process (i.e., job resources --> engagement --> organizational commitment). In addition, some cross-links between both processes were hypothesized. Structural equation modeling was used to simultaneously test the hypotheses in a sample of Finnish teachers (N=2038). The results confirmed the existence of both processes, although the energetical process seems to be more prominent. More specifically, (1) burnout mediated the effect of high job demands on ill health, (2) work engagement mediated the effects of job resources on organizational commitment, and (3) burnout mediated the effects of lacking resources on poor engagement. The robustness of these findings is underscored by the fact that they were obtained in one half of the sample (using random selection) and cross-validated in the other half.