Adverse effects associated with calcineurin inhibitors may impact their clinical utility in some patients. This study characterizes the clinical outcomes of liver transplanted (LT) patients who experienced diabetes mellitus (DM) on tacrolimus-based regimen and were converted to cyclosporine-based therapy. Since January 2002, all patients with DM on a tacrolimus-based regimen were recruited and converted to cyclosporine-based therapy, after a 6-month minimal follow-up after LT. Clinical and laboratory data related to the clinical course of the patients were recorded. Twenty-five patients were included after a median delay of 54 months after LT [seven women and 18 men, 51 years (range 30-69)]. There were 11 patients with insulin-treated DM (ITDM), 14 patients with noninsulin-treated DM (NITDM), and the glycemic control was poor (HbA1c > 6.5%) in 13/25 patients (52%). After a median follow-up of 20 months after conversion, there were four patients with ITDM, 17 patients with NITDM, and four patients without DM, and the glycemic control was poor in 3/25 patients (12%). Four patients returned to tacrolimus because of arterial hypertension or digestive side-effects. In conclusion, our results suggest that conversion from tacrolimus to cyclosporine in stable LT patients with DM is well tolerated and beneficial on glycemic control. Liver Transpl 12:659–664, 2006. © 2006 AASLD.