Early mobilisation of critically ill patients is considered a standard practice in the ICU today but still lacks a uniform definition. However, an early start, i.e., within 48–72 h after ICU admission, is essential for positive effects on patient outcomes. Mobilisation of critically ill patients should include active and passive forms of mobilisation and be carried out using a goal-directed protocol. Interprofessional cooperation in the critical care team is also crucial for success. When early mobilisation is implemented, there are both short- and long-term benefits. Reduced ventilation and intensive care length of stay improved physical function, and long-term cognitive benefits have been demonstrated. At the same time, early mobilisation has been well shown to be safe. Only the aspect of the optimal dose and when an excessive workload with adverse effects may occur is insufficiently investigated. Thus, individual planning and treatment management by the interprofessional team is essential. In addition, the combined effects of high-protein nutrition and early mobilisation are currently being investigated, with promising signs of synergistic effects. In summary, integrating early mobilisation into intensive care therapy is a safe approach to improve the outcomes of our ICU patients.