Work-related rumination is not a single construct, but consists of a dimension associated with negative emotions or affect (affective rumination), and a dimension associated with reflective thinking and applying strategies to solve problems (problem-solving pondering). In this three-wave longitudinal study across two years (N = 630) we investigated whether the relationships between work-related rumination, off-job recovery, and creativity at work varied along the two dimensions of work-related rumination. In addition, we tested whether the relationships followed normal, reversed, or reciprocal causation. The results showed, first, that in a one-year perspective affective rumination, but not problem-solving pondering, was negatively related to off-job recovery and that problem-solving pondering, but not affective rumination, was positively related to creativity at work. Second, in a two-year perspective, reversed effects were detected as creativity at work was negatively related to affective rumination and positively to off-job recovery. Our results suggest that the quality of work-related thoughts determines whether the outcome is beneficial or detrimental. Occupational health interventions that only advise employees to stop thinking about work during off-job time, may therefore be too simplistic.