Background: Familial partial lipodystrophies are rare monogenic disorders that are often associated with diabetes. In such cases, it can be difficult to achieve glycaemic control. Case report: We report a 34-year old woman with familial partial lipodystrophy type 2 (Dunnigan) and diabetes; her hyperglycaemia persisted despite metformin treatment. A combined intravenous glucose tolerance–euglycaemic clamp test showed severe insulin resistance, as expected, but also showed strongly diminished first-phase insulin secretion. After the latter finding, we added the glucagon-like peptide-1 receptor agonist liraglutide to the patient's treatment regimen, which rapidly normalized plasma glucose levels. HbA 1c values < 42 mmol/mol (6.0%) have now been maintained for over 4 years. Conclusion: This case suggests that a glucagon-like peptide-1 receptor agonist may be a useful component of glucose-lowering therapy in individuals with familial partial lipodystrophy and diabetes mellitus.