There is a paucity of data analysing the reasons for primary non-adherence following first prescription of insulin among patients with uncontrolled type 2 diabetes mellitus (T2DM) in India. To address this, and to attempt to understand these reasons, an exploratory study was undertaken to assess the prevalence of primary non-adherence with insulin and barriers to insulin initiation in these patients. Study participants were randomly selected from patients with T2DM who visited the diabetes clinic of a tertiary care teaching public hospital in Rishikesh, Uttarakhand, India, and were prescribed insulin for the first time in last 2-year period. All participants were evaluated for history of primary non-adherence, and those who were non-adherent were subsequently interviewed face-to-face using a modified, validated semi-structured questionnaire to identify the reasons for primary non-adherence. A focused group discussion was also conducted with eight physicians to elicit their views about reasons for primary non-adherence with insulin. A total of 225 patients were identified and interviewed; of these, 105 were identified with a history of primary non-adherence and underwent a subsequent face-to-face interview. There was a high prevalence of primary non-adherence with insulin among the participants of this study. The main reasons for non-adherence were low self-efficacy, doubt about clinical benefits of insulin, fear of hypoglycaemia, needle phobia, unaffordability of insulin and blood glucose monitoring device, strong faith in alternative medicines and mythical ideologies, and fears of insulin being addictive and that it may cause rapid aging. With the high prevalence of primary non-adherence, and the multitude of reasons for this, it is clear that we need to eliminate these barriers to treatment. Thus, provision of dedicated diabetes educators in each diabetes clinic and availability of cost-effective insulin and blood glucose monitoring devices for the underprivileged population are key to achieve this.