Diabetes mellitus is a debilitating disease that is estimated to affect 366 million people by the year 2030. Type 2 diabetes mellitus (T2DM) is characterized by a progressive decline in pancreatic β-cell function and increased insulin resistance, and accounts for approximately 90% of people with diabetes. Oral antihyperglycaemic agents are extensively used in the treatment of T2DM. Thiazolidinediones are insulin sensitizers developed specifically for T2DM, which act via activation of peroxisome proliferator-activated receptors (PPARs). Pioglitazone is a thiazolidinedione that displays high affinity for PPARγ(1) and PPARγ(2), which are predominately expressed in adipose tissue. This review examines the published literature comparing the efficacy and tolerability of pioglitazone with other oral antihyperglycaemic agents in the treatment of patients with T2DM. Glycosylated haemoglobin, fasting glucose, insulin parameters and β-cell function are all improved with pioglitazone treatment, with efficacy similar to third-generation sulfonylureas, metformin and dipeptidyl peptidase-4 inhibitors. Pioglitazone reduces vascular risk and inflammatory markers, and improves carotid intima media thickness independent of its glycaemic effect. When compared with rosiglitazone, pioglitazone is associated with a reduction in the risk of hospitalization for acute myocardial infarction. Blood pressure is reduced and lipid profiles are favourably improved with pioglitazone; however, an increased risk for the development/exacerbation of heart failure, which is related to the increased incidence of oedema due to fluid retention, and fractures remain a concern. A low incidence of hypoglycaemia is observed with pioglitazone, especially compared with sulfonylureas. In conclusion, pioglitazone is an effective oral antihyperglycaemic agent with additional cardiovascular and lipid benefits that allows for the successful management of patients with T2DM.