Joint National Commission (2017) reported that Hypertension affects nearly 26 percent of adult population all over world. Hypertension can be alone independent factor for adverse cardiovascular disorders, (Joint National Commission) defines hypertension as blood pressure >140/90 mmHg. Persons whose blood pressure goes above optimal levels, but not clinical hypertension (systolic blood pressure of 120–139 mm Hg or diastolic blood pressure of 80–89 mm Hg, are defined as “Pre–hypertensive”. Deep breathing exercise is one of the non –pharmacological, successful method to use in maintaining the normal blood pressure among patients with hypertension and also Continuous practicing of deep breathing exercise can reduce medicine usage thereby it can be used routinely as a corresponding method of treatment for hypertension. Deep breathing exercise will reduce the side effects of medicine in case of hypertension & also decreased its usage. The objective of present study is to Assess the Effectiveness of Self Instructional Module (SIM) on Knowledge of Hypertension among Pre–hypertensive Staff and Effectiveness of Deep Breathing Exercises in Lowering blood pressure in Pre– Hypertensive Staff of age 25–40 years, working in different non medical faculties of SGT University Gurugram. The non–probability purposive sampling technique was used to select 60 Pre– Hypertensive Staff of age 25–40 years, working in different non medical faculties of SGT University Gurugram one group pre test post design was used in present study. Samples were selected by non probability sampling technique. The tool consists of demographic variables and structured tool to assess knowledge on hypertension. Reliability was calculated by using split half method. Analysis of the data was done using descriptive and inferential statistics.