Introduction: Diabetes mellitus is a wide spread metabolic disorder characterized by hyperglycemia. In Pakistan, many traditional or medicinal plants are being used to treat ailments or disorders, both in children and adults. To date, there has been no research study done to investigate the effect of Morus alba (white mulberry) leaves on blood glucose levels of individuals with type II diabetes mellitus in Pakistan. The present study was conducted to determine the effect of Morus alba (white mulberry) leaf powder on glycated haemoglobin (HbA1c) of patients with type II diabetes mellitus. Methods: The study design of this study was a randomised controlled trial. Eighty patients with type II diabetes mellitus were randomly selected from the Fatima Memorial Hospital and were equally divided into two groups - control group and experimental group. Patients in the control group were asked to follow their regular hypoglycaemic medications, while patients in the experimental group were administered with 500mg of Morus alba leaf tablet twice a day, 15 minutes before breakfast and dinner, along with their regular hypoglycaemic medications. HbA1c of patients in both groups were assessed on day zero before the study and on the ninetieth day at study completion. Results: HbA1c of patients in the control group at baseline was 8.92% and 8.91% at final, whereas HbA1c of patients in the experimental group at baseline was 9.13% and 8.59% at final. Conclusion: The results of this study concluded that Morus alba leaves had a significant effect in lowering high blood sugar levels.