Background: A study was conducted to assess the effectiveness of Self-Instructional Module on knowledge regarding dietary approaches to stop hypertension among hypertensive patients in selected hospital, Sikar, Rajasthan. A total sample of 60, hypertensive patients were selected using purposive sampling technique. The objectives of the study were to assess the level of knowledge among hypertensive patientsregarding dietary approaches to stop hypertension (DASH) before and after intervention (Self Instructional module) and to determine the effectiveness of self-instructional module on level of knowledge regarding DASH among hypertensive patients. The final objective was to find out the association between pre-test level of knowledge and selected demographic variables. Materials and Methods: A one-group pre-test post-test design was used to conduct the study. 60 hypertensive patients from selected hospital were enrolled using non-probabilitypurposive sampling technique. The conceptual framework of the study was based on Ludwig von Bertalanffys General System Model. Tools used for data collection were demographic Performa and structured knowledge questionnaire. Results: Data analysis was done using descriptive and inferential statistics. Findings of the study revealed that the mean post-test knowledge score 23.00±2.7 was significantly higher than the mean pre-test knowledge score 10.00±2.3 with the Paired t value computed [31.60**, df=59] was statistically significant (P<0.01 level). Significant association was observed between level of knowledge and gender at 0.05 level. Conclusion: The findings of the study confirmed tha the Self-instructional module was significantly effective in improving the knowledge regarding DASH among hypertensive patients.