This review updates the pharmacology, efficacy, safety, and tolerability of liraglutide, a glucagon-like peptide 1 (GLP-1) analog approved for the treatment of type 2 diabetes (T2DM) in January 2010. MEDLINE was searched (May 2009-January 1, 2011) for articles in English, using the terms liraglutide, NN2211, incretin mimetic, glucagon-like peptide (GLP)-1, and GLP-1 receptor agonist. Abstracts from key meetings (ADA 2009 and 2010, AACE 2010, EASD 2009, and EASD 2010) were also searched for relevant data. A GLP-1 analog with pharmacokinetic properties allowing once-daily administration via subcutaneous injection, liraglutide has shown clinical benefits when used as monotherapy or in combination. Liraglutide monotherapy has demonstrated efficacy in reducing hemoglobin A1c (A1C) and body weight, with low risk for hypoglycemic events. Liraglutide has also been studied in combination with metformin, glimepiride, and rosiglitazone for the treatment of T2DM. Extension studies within the Liraglutide Effects and Action in Diabetes clinical program have demonstrated the efficacy of liraglutide over 2 years of treatment. Overall, liraglutide has been shown to be well tolerated, with dose-dependent nausea, vomiting, and diarrhea being the most commonly reported adverse events in clinical trials. Extended dosing periods have demonstrated the durability of response of liraglutide with respect to glycemic control, lack of weight gain, and blood pressure benefits. Compared with exenatide and sitagliptin, liraglutide seems to offer greater improvements in A1C, fasting plasma glucose, and body weight. Adverse events commonly associated with liraglutide in clinical trials included nausea and hypoglycemia. Emerging data suggest that liraglutide may be a useful option for patients with T2DM.