OBJECTIVES: The purpose of this study was to investigate the association of diabetes-related knowledge and treatment adherence with glycaemic control among patients with type 2 diabetes mellitus (T2DM) in Pakistan. METHODS: The study was designed as a questionnaire-based, cross-sectional analysis. T2DM patients attending a public outpatient clinic in Sargodha, Pakistan, were targeted for the study. In addition to the demographic information, the Urdu version of Michigan Diabetes Knowledge Test and Morisky Medication Adherence Scale were used for data collection. Patients’ medical records were reviewed for glycated haemoglobin levels (HbA1c). Descriptive statistics were used to elaborate sociodemographic characteristics. The Spearman’s Rho correlation was used to measure association of disease-related knowledge and treatment adherence with glycaemic control. SPSS v 20.0 was used for data analysis and p < 0.05 was taken as significant. RESULTS: In total, 392 T2DM patients were included in the study. The mean age (SD) of these patients was 50.77 ± 9.671 years, 56.6% were males and 90% (n = 353) of respondents were married. The mean (SD) duration of disease was 5.58 (4.09) years with median HbA1c of 9.00 (IQR = 8.20–10.40). The median knowledge score was 8.0 (IQR = 6.0–10.0), while the median adherence score was 4.7 (IQR = 3.0–6.0). HbA1c had non-significant and weak negative association with diabetes-related knowledge (r = −0.036, p = 0.404) and treatment adherence (r = −0.071, p = 0.238). CONCLUSIONS: There was negative association reported between HbA1c, treatment adherence and diabetes-related knowledge. Greater efforts are clearly required to investigate other factors affecting glycaemic control among T2DM patients in Pakistan.