BACKGROUND: Catatonia is a severe motor syndrome found in approximately 10% of all acute psychiatric hospital admissions. It can occur in various psychiatric diseases. We report the first case report of catatonia during cannabis withdrawal. CASE PRESENTATION: Mr. A, a 32-year-old man, reported to have daily smoked approximately 20 grams of cannabis since aged 11 years. Mr. A was incarcerated and was reported three weeks later to the medical department for having completely ceased talking and eating. At admission in our department, the patient presented with classical catatonia symptoms (Bush-Francis Catatonia Rating Scale (BFCRS) score = 39/69). All laboratory results and brain MRI were normal. Six weeks after his admission and treatments by lorazepam and memantine, his BFCRS score was 0/69. DISCUSSION: This single-case study highlights the previously under-reported emergence of physical and motor symptoms following cannabis withdrawal. Pathophysiological aspects of abrupt cannabis cessation contributing to GABA/glutamate balance dysregulation and to catatonia are discussed.