Background Adherence to insulin and blood glucose monitoring (BGM) is insufficient in adolescents and young adults (AYAs) with type 1 diabetes (T1D) worldwide and in Qatar. Little is known about the factors related to being aware of suboptimal adherence and the beliefs related to suboptimal adherence in this group. This qualitative study investigated factors related to awareness of, and beliefs about suboptimal adherence, as well as the existence of specific action plans to combat suboptimal adherence using the I-Change model. Methods The target group was comprised of 20 Arab AYAs (17–24 years of age) with T1D living in Qatar. Participants were interviewed via semi-structured, face-to-face individual interviews, which were audio-recorded, transcribed verbatim, and analyzed using the Framework Method. Results Suboptimal adherence to insulin, and particularly to BGM, in AYAs with T1D was identified. Some AYAs reported to have little awareness about the consequences of their suboptimal adherence and how this can adversely affect optimal diabetes management. Participants also associated various disadvantages to adherence (e.g., hypoglycemia, pain, among others) and reported low self-efficacy in being adherent (e.g., when outside home, in a bad mood, among others). Additionally, goal setting and action-planning often appeared to be lacking. Factors facilitating adherence were receiving support from family and healthcare providers, being motivated, and high self-efficacy. Conclusions Interventions that increase awareness concerning the risks of suboptimal adherence of AYAs with T1D are needed, that increase motivation to adhere by stressing the advantages, creating support and increasing self-efficacy, and that address action planning and goal parameters.