Unfinished work tasks have been identified as a significant job-related stressor in recent occupational stress research. Extending this research, we examine how and when not finishing one's tasks by the end of the work week affects work-related rumination at the weekend. Drawing on control theory, we examined competence need satisfaction as a mediating mechanism that links unfinished tasks at the end of the work week to work-related rumination at the weekend. Furthermore, we scrutinized whether proactive work behavior within the work week may neutralize the detrimental effects of unfinished tasks on competence need satisfaction and rumination. Using diary methodology, we collected weekly observations from 58 employees at the beginning and a...