OBJECTIVES: Achieving therapeutic goals in Type 2 diabetes often becomes more difficult as the disease progresses; many patients eventually require treatment beyond oral hypoglycaemic agents (OHA). The objective of this meta-analysis was to investigate which injectable therapies were either superior/inferior to bedtime-administered insulin glargine, (glargine) for key clinical outcomes. METHODS: A systematic review of all published glargine clinical trials (prior to October 2005) was conducted. Based on pre-defined inclusion criteria, the review encompassed all randomised controlled trials of at least eight-weeks duration that compared combination therapies (injectable therapy and OHA(s)), in insulin naïve patients. A random effects model was employed to incorporate the variability in between-study conditions. RESULTS: Seven trials met the specified criteria, with glargine chosen as the reference regimen. Although biphasic insulin aspart (BIA) and insulin lispro 75/25 were more efficacious than glargine at reducing HbA1c (in unadjusted (adjusted) analyses further reductions of -0.46 % (-0.41) and -0.39 % (-0.40) respectively were observed), this increase in efficacy was also associated with relative increases in the risk of experiencing hypoglycaemic events for both insulins and increased weight gain for BIA. Compared to glargine, exenatide and NPH were equally as efficacious at reducing HbA1c, although patients taking exenatide also benefited from weight reduction and a reduced risk of experiencing a nocturnal hypoglycaemic event. With respect to fasting blood glucose, exenatide, insulin lispro 75/25 and NPH were less efficacious than glargine. CONCLUSION: This meta-analysis found a slight increase in efficacy observed with the two twice-daily insulin regimens compared to glargine; however this result must be carefully balanced against the observed increase in adverse events, especially for patients where weight gain or hypoglycaemic events may be an issue. When glargine was compared to exenatide, similar HbA1c reduction was found but exenatide treated patients had fewer nocturnal hypoglycaemic events and experienced weight loss.