Background: Regarding demographic change, the rise in the working age and increase in long-term illnesses is a task for society to maintain the health of employees and return employees with long-term illnesses to work. In many countries like Germany, gradual return to work (GRTW) is used more and more frequently to achieve the full work capacity of employees, but little is known about its facilitators and obstacles.Methods: This qualitative study will examine the current implementation of GRTW by means of 32 narrative interviews and 10 group discussions from different perspectives. Therefore, we will ask returning employees, their accompanying trusted person during GRTW in the company and organisations, and supra-organisational experts throughout Germany about their experiences with GRTW and attitudes toward the measure. The verbal data obtained will be analysed using the Documentary Method of Interpretation, focusing on the implicit and action-guiding knowledge of the study participants. Discussion: This study will reveal facilitating and hindering factors of the recommendation, planning, utilisation, and implementation of GRTW in Germany. Future findings of the study can contribute to an improved use of GRTW, thus promoting a sustainable return to work. Based on this, recommendations for action can be developed for different actors.Trial registration: German Clinical Trials Register (ID: DRKS00022892, October 1st, 2020).