Background <p>Growth impairment is a serious concern in Transfusion dependent thalassemia (TDT) patients. Decreased height/length in these patients is a result of multiple factors such as nutrition, recurrent infections, iron overload, chronic anemia, multiple vitamin and mineral deficiency. Zinc is one such micronutrient which is deficient in TDT patients and has a role in enhancing growth.</p> Objectives <p>To determine the effect of oral zinc supplementation on linear growth of transfusion dependent thalassemia patients. To study the immuno-modulator role of zinc in respiratory infections and the adverse effects of zinc.</p> Methods <p>Forty TDT patients whose heights were &lt; 50th centile were randomly divided into two groups, each group consisted of 20 patients: Group I received oral zinc sulphate (40 mg per day) and Group II served as control group and received placebo (lactose) supplementation. Patients were followed for 12 months and mean of height and frequency of respiratory infections was compared in both the groups at the end of 12 months. Adverse effects of zinc were studied in Group1.</p> Results <p>TDT patients who had their height/length below 3rd centile and between 3rd and 50th centile were 32.5% and 67.5% respectively No statistically significant difference in height was noted between the two groups. There was no statistically significant difference in frequency of respiratory infections in both the groups (<i>P</i> = 1.00). Most common adverse effects of zinc reported was metallic/distortion of taste followed by nausea/vomiting and abdominal discomfort, while mouth sores was the least common adverse effect.</p> Conclusion <p>Oral Zinc supplementation had no effect on linear growth and in prevention of respiratory infections in TDT patients.</p>