Several types of interventions to help people detach from work have been tested, but so far, no tests of different types of planning have been conducted. This field experiment tested the effects of goal setting combined with making implementation intentions on psychological detachment in the evening, and its effect on fatigue the next day, compared to an only goal setting condition and a control group without an intervention. The effects of the interventions were measured by means of a daily diary for a period of two weeks. We hypothesized a stronger effect on detachment in the evening and fatigue the next day of the implementation intention intervention for those not habitually planning. Contrary to our expectation, neither intervention had a positive effect in comparison to the control group. The daily effects on psychological detachment of the combined goal-setting implementation intention condition were negative for individuals who had a high general tendency to plan, as shown by the significant cross-level interactions of the moderated mediation model. We discuss these results in light of future interventions.