Functional neurological disorders (FNDs) are complex disabling conditions requiring a multiple rehabilitation intervention. Here, we propose a new use of whole-body cryostimulation (WBC) that was implemented in a multidisciplinary rehabilitation programme in a wheelchair-ridden woman diagnosed with FND and other comorbidities. WBC is a promising adjuvant treatment in various conditions of rehabilitation interest, mainly because of its wide range of rapid effects, from anti-inflammatory to pain and autonomic modulating effects. The 4-week program included physiotherapy, nutritional intervention, psychological support, and WBC (−110 °C for 2 min). Questionnaires to assess disease impact, pain level, fatigue and sleep quality were administered. At discharge, improvements in body composition, haematological biomarkers, physical performance, and questionnaire scores were observed. The patient was able to walk independently with a walker for medium distances and reported unprecedented improvements, particularly in functional parameters and questionnaire scores. Although the extent to which WBC per se contributed to the measured improvements cannot be ascertained, subjective reports and our clinical observations indicate that WBC, the only intervention not previously experienced by the patient, acted as a booster for the rehabilitation interventions. Further research will be necessary to rule out any possible placebo effect and to confirm the effects of WBC on FND.