The present problem was undertaken for the study of Mental Health of senior secondary students in relation to their decision making style. The study was carried out on a sample of senior secondary school students belonging to Ghaziabad district. The tools used for the collection of data are Mental Health Inventory by Jagdish & Srivastava and Decision Making Style by Dr. Noorjahan N. Ganihar. The data, is analyzed to use ‘t’-test. The result shows that there is no significant difference between the mental health of male and female senior secondary students in relation to their decision making style & there is a significant difference between the Mental health and Decision making style of senior secondary students.