Background: The discovery of insulin over a century ago significantly advanced the treatment of diabetes mellitus (DM). Effective glycemic control in patients on insulin therapy is influenced by a variety of factors. While developed countries have transitioned fully to insulin analogs, abandoning recombinant insulin, Mongolia lacks comprehensive research on how different insulin formulations influence glycemic control. This gap highlights the need for targeted improvements in therapy effectiveness and service quality. Materials and methods: The cross-sectional study was conducted at the Central Hospital of the Mongolian National University of Medical Sciences, including 183 diabetic patients aged 18-65 years. Participants were managed by endocrinologists and participated in a survey consisting of 44 questions alongside physical measurements. Data were 78 analyzed using SPSS version 25, with a significance threshold of p<0.05. Results: The study population had a mean age of 56.7 ± 11.0 years, with 55.2% (n=101) males. The mean duration of diagnosed DM was 12.6 ± 6.33 years, and the mean duration since the initiation of insulin therapy was 6.77 (1-24) years. The mean glycated hemoglobin (HbA1c) was 10.5%, with 87.4% of the participants categorized under poor glycemic control and only 5.5% maintaining optimal levels. Insulin usage was predominantly recombinant (60.7%), with analogue at 32.2%, and mixed regimens at 7.1%. Usage of insulin pens was reported by 43.2% of the participants. The daily insulin dosage ranged from 10 to 71 units, averaging 37.2 ± 13.7 units. Multivariate logistic regression analysis confirmed that inadequate knowledge about insulin therapy is an independent risk factor (OR; 95% CI = 1.48; 1.21 10.32). When adjusting for confounding factors, the average glycated hemoglobin (HbA1c) levels in the group with inadequate knowledge was significantly higher (11.8%) compared to the group with adequate knowledge, where it was significantly lower (10.2%). Conclusion The use of analog insulin among patients with type 2 diabetes undergoing insulin therapy is relatively low (32%), and glycemic control is poor (87%). Therefore, it is necessary to increase the use of analog insulin and improve glycemic control. Inadequate knowledge about insulin therapy negatively affects glycemic control in patients with type 2 diabetes (OR; 95% CI = 1.48; 1.21-10.32). Therefore, it is essential to enhance patients’ knowledge.