Despite being recognized as a detrimental behaviour with negative repercussions for performance and well-being, research on workplace procrastination is limited, with most studies focusing on students. Drawing on the Conservation of Resources Theory and the Effort-Recovery Model, this study expands the literature on procrastination at work by proposing workaholism as an additional triggering factor. Moreover, it investigates the processes that could drive (i.e. lack of psychological detachment) or reduce this relationship (i.e. employee welfare, namely the extent to which employees perceive their organizations as valuing and caring for them). We collected data on 795 employees by administering a survey in three waves, each separated by a one-month interval. A longitudinal moderated-mediation model analysis revealed that a) lack of psychological detachment, as an indicator of resource depletion, mediates the association between workaholism and procrastination; moreover, b) this relationship is moderated by employee welfare. Specifically, the links between workaholism and lack of psychological detachment, as well as workaholism and procrastination via lack of psychological detachment, are weaker when employee welfare is high. Organizations should adopt supportive actions to help workaholics in promoting post-work recovery and enhancing employee well-being. These actions can help prevent resource depletion, and, in turn, reduce procrastination at work.