Background: Rational prescribing of insulin and improved patient knowledge, attitude and practice regarding insulin usage will optimise insulin therapy in diabetes mellitus. Objective: The study aims to assess the knowledge, attitude, practice of insulin therapy. Study method: A cross sectional study was done in various in patient departments using KAP questionnaire. A total of 70 filled questionnaires were evaluated and analysed using Chi- Square test. Results: Knowledge, attitude and practice study found that better knowledge, Attitude and Practice among participants irrespective of their family history and educational status, towards insulin therapy. The relation between education status of participants and their knowledge about insulin discontinuation once the blood sugar levels normalize (p value=0.047) as well as their practice of checking blood sugar level in home (p value=0.025) were found to be statistically significant. This data suggests that mean knowledge score was more for illiterate (14.21) followed by high school and primary school. Conclusion: There is a need to educate the patient about various aspects of insulin therapy including dosing, storage, site of injection, common side effects and life style modifications. Clinical pharmacist can play a vital role in monitoring and optimization of insulin therapy.