Many Australian adults with type 2 diabetes mellitus (T2DM) do not follow recommended self-management behaviours that could prevent or delay complications. This exploratory study aimed to investigate the factors influencing self-management of T2DM in general practice. Semi-structured qualitative interviews were conducted with patients with T2DM (n = 10) and their GPs (n = 4) and practice nurses (n = 3) in a low socioeconomic area of Sydney, New South Wales, Australia. The interviews were analysed thematically using the socio-ecological model as a framework for coding. Additional themes were derived inductively based on the explicitly stated meaning of the text. Factors influencing self-management occurred on four levels of the socio-ecological model: individual (e-health literacy, motivation, time constraints); interpersonal (family and friends, T2DM education, patient-provider relationship); organisational (affordability, multidisciplinary care); and community levels (culture, self-management resources). Multi-level strategies are needed to address this wide range of factors that are beyond the scope of single services or organisations. These could include tailoring health education and resources to e-health literacy and culture; attention to social networks and the patient-provider relationship; and facilitating access to affordable on-site allied health services.