Introduction: Lithium is a treatment used for bipolar affective disorder and depression. It is by far the best treatment for this particular disorder; however, it remains a medication that is, compared with most psychotropic medications, more difficult to handle, this is largely due to its narrow therapeutic index and its long-term side effects. Nurses in psychiatry must be aware of the side effects and dangers this treatment can cause in both long and short terms.Material(s) and method(s): To answer our research question, we conducted a study which aims on the assessment of nurses and their knowledge when it comes to lithium's manipulation in treating patients with bipolar disorder, to eventually create a protocol for the use of lithium by nurses in treating patients with this disorder.Results: Nurses in psychiatry had a poor knowledge about Lithium use and side effects.Consclusions: Training sessions are recommended.