Introduction: Diabetes is a major public health issue and one of the causes of disability and mortalityworldwide. One of the main challenges to controlthis disease is lack ofadherence to therapeutic regimen. Therefore, this study aimed to evaluate barriers to adherence to therapy in patients with diabetes.

Methodology: This qualitative study was conducted on15 male and female patients with type II diabetes using semi-structured interviews. Data was collected during November 2015-June 2016. In addition, data analysis was performed using conventional qualitative content analysis.

Results: Analysis of the findings of a series of extracted themes revealed three main themesas barriers to adherence to therapy in patients with type II diabetes, as follows: "poor medical team performance" with subcategories of providing incomplete and contradictory information, non-cooperative performance of healthcare teams, failure to meet the needs of clients, loss of time, "social dilemma" with subcategories ofoccupation conditions, reaction of others, lack of harmony in the family and "personal distress" with subcategories of stress and depression, financial stress, effects of age, interference of personal desires with treatment goals.

Conclusion: According to the results of this study, barriers to adherence to therapy in Iranian people with diabetes was related to the people's family and social background, which could turn to a challenge forthe patient, leading to neglectof health behaviors. Identification of these factors by policy makers and healthcare providers is essentialto facilitatetheattitude of patients and their commitment to adherence to therapy and to prevent irreparable complications of diabetes.