Prolonged stays in the intensive care unit (ICU) cause difficulties in rehabilitation and other disorders for patients. This problem is exacerbated in the case of pediatric patients. The use of virtual reality can help with the lack of external stimuli and contribute as potential nonpharmacological therapies in some patient rehabilitation processes. To this end, we have developed a virtual reality application for use in the pediatric ICU as a tool for the treatment and rehabilitation of delirium. The tool consists of two applications: an immersive environment for a virtual reality headset used by the patient, and a web application managed by a therapist with which they can customize, control, adapt, and analyze in real time everything that happens in the patient's virtual world. Our application has been designed jointly with a university center and a hospital, and initial evaluations indicate the results to be promising.