Background: The effects of liraglutide on body weight and hemoglobin A1C (HbA1c) level vary greatly. The cost of this drug negatively affects treatment adherence. Aim: To reveal the baseline patient characteristics, associated with a better response to liraglutide. Materials and methods: A total of 41 patients with BMI of 39.63 ± 7.59 kg/m2 who received liraglutide injection up to 1.8 or 3.0 mg/day for 6 months were enrolled. Demographic and anthropometric data, parameters of glycemic control, food intake, hormones and responses to the eating behavior questionnaire were collected. Results: Weight reduction was dose-dependent (p = 0.007). Liraglutide was not effective in patients with BMI >45 kg/m2. The baseline HbA1c level was a significant factor for HbA1c reduction. Lower leptin and higher glucagon-like-peptide 1 concentrations might predict better weight loss response to liraglutide. Conclusion: Drug-specific efficacy predictors were assumed; thus, further studies are needed to prove their significance.