The rapidly-acting antidepressant properties of ketamine are a trend topic in psychiatry. Despite its robust effects, these are ephemeral and can lead to certain adverse events. For this reason, there is still a general concern around the off-label use of ketamine in clinical practice settings. Nonetheless, for refractory depression, it should be an indication to consider. We report the case of a female patient admitted for several months due to a treatment-resistant depressive bipolar episode with chronic suicidal behaviour. After repeated intravenous ketamine infusions without remarkable side effects, the patient experienced a complete clinical recovery during the 4 weeks following hospital discharge. Unfortunately, depressive symptoms reappeared in the 5th week, and the patient was finally readmitted to hospital as a result of a suicide attempt.