Objective: We investigated the efficacy and safety of liraglutide 3 mg daily in combination with diet and exercise 2, 4, and 6 months after initiation in real-world settings in Korea. Methods: People first using liraglutide starting in 2018 were recruited from ten sites in Korea. Body weight and body mass index (BMI) were measured after 2, 4, and 6 months and compared with baseline values. Results: The full cohort comprised 769 participants: 672 in the 2-month group, 427 in the 4-month group, and 219 in the 6-month group. The baseline mean ± standard deviation of BMI and body weight were 32.2 ± 5.1 kg/m2, and 87.5 ± 18.8 kg, respectively. Body weight and BMI decreased after initiation of liraglutide treatment: −2.94 kg and −1.08 kg/m2 at 2 months; −4.23 kg and −1.55 kg/m2 at 4 months, and −5.14 kg and −1.89 kg/m2 at 6 months (all P < 0.001). In the 6-month cohort, 52.5% and 18.3% of subjects lost ≥5% and ≥10% of body weight, respectively. After 6 months, systolic and diastolic blood pressure decreased significantly by 3.90 and 1.93 mmHg, respectively. In those with diabetes mellitus, HbA1c and fasting glucose levels decreased significantly by 1.14% and 27.8 mg/dl, respectively. Among all participants, 27.6% experienced adverse effects, including nausea (20.8%), vomiting (5.2%), diarrhoea (2.5%), and skin rash (3.6%). Documented reasons for discontinuation of treatment were lack of effect (4.4%), adverse events (4.3%), and high cost (3.1%). Conclusions: In real-world settings in Korea, daily treatment with liraglutide 3 mg was associated with clinically meaningful weight loss without serious adverse events.