Lithium has for 60 years been the main mood stabilizer for bipolar disorder and some patients have now been treated with lithium for decades without any symptoms or side effects. We present a case with excellent response to lithium during 28 years and with recurrence of a hypomania and subsequently a severe depressive episode following planned discontinuation of lithium. Discontinuation of lithium should be carefully evaluated in patients with a good response to lithium, and the specific reasons for discontinuation should be considered.