Aims Using a pragmatic approach, the LIRA-PRIME trial aims to address a knowledge gap by comparing efficacy in controlling glycaemia with glucagon-like peptide-1 analog liraglutide vs oral antidiabetic drugs (OADs) in patients with type 2 diabetes (T2D) uncontrolled with metformin monotherapy in primary care practice. We report the study design and patient baseline characteristics. Materials and methods This 104-week, two-arm, open-label, active-controlled trial is active in 219 primary care practices across nine countries. At screening, eligible patients with T2D were at least 18 years of age, had been using a stable daily dose of metformin >= 1500 mg or the maximum tolerated dose for >= 60 days, and had a glycated haemoglobin (HbA1c) of 7.5% to 9.0%, measured <= 90 days before screening. Patients were randomized (1:1) to liraglutide or OAD, both in addition to pre-trial metformin. Individual OADs were chosen by the treating physician based on local guidelines. The primary endpoint is time to inadequate glycaemic control, defined as HbA1c above 7.0% at two scheduled consecutive visits after the first 26 weeks of treatment. Results The trial randomized 1997 patients with a mean (standard deviation) age of 56.9 (10.8) years, T2D duration of 7.2 (5.9) years (range, <1-47 years), and HbA1c of 8.2%. One-fifth of patients had a history of diabetes complications, and most were overweight (24.8%) or had obesity (65.3%). Conclusions This pragmatically designed, large-scale, multinational, randomized clinical trial will help guide treatment decisions for patients with T2D who are inadequately controlled with metformin monotherapy and treated in primary care.