Context: Managing diabetes efficiently demands a simple, safe, convenient and economical therapy. This study was done to understand the simplicity, safety, convenience and cost effectiveness of using pen versus syringe devices in patients on long-term insulin therapy. Design: This prospective observational study was conducted at the endocrine outpatient department of a universityaffiliated teaching hospital in North India. The investigator interviewed patients using a self-made questionnaire after obtaining consent; patients were scored based on their answers. A high score represented a poor response. A total of 90 completed questionnaires (45 from each group) were obtained. Results: Mean simplicity, safety and convenience score among the pen users was 5.31 ± 0.51, 5.4 ± 0.89 and 4.13 ± 1.04 respectively, as compared to 9.78 ± 1.43, 8.09 ± 2.02 and 8.67 ± 0.56 in syringe users respectively. The difference in these scores was statistically significant (p=0.0001). All patients felt that treatment using pen device was costlier when compared to using syringes, with pen users spending Rs1,756 per month on their insulin therapy, as compared to syringe users, who spent Rs590 per month. Among insulin pen users, 22.2% had optimal glycated haemoglobin levels (6-7.5%) as compared to 2.2% among syringe users, and this difference was statistically significant (p=0.007). Conclusions: An insulin pen is simple, safe and convenient to use, and may provide better glycaemic control. Treatment with a pen device is costlier, which may be due to the higher use of analogue insulin among pen users.