Aim: To analyse the potential cognitive factors and family functioning related to adherence among type 1 diabetic mellitus adolescents in India. Method: Standardised tools such as Hospital Anxiety and Depression Scale (1983); Self Care Inventory-R(2001); Emotional Regulation(2003); Family Assessment Device(1983) was administered on 84 adolescents who had mean age of 15.4 years; their age of diabetes onset was 9.83 years; the mean duration of diabetes mellitus was 5.5 years; 37% boys were participants in the current study and 52% of the participants hailed from urban and semi-urban areas. Results: The results were analyzed through the statistical tool Spearman correlation which revealed significant relationship between family functioning and adherence (p=.318**); behavioural control practiced by family members and adherence (p=.339**); affective involvement and adherence (p=.216*); communication and adherence (p=-.261*).Thus, when an individual is able to evaluate their family environment, they are more likely to adhere to their treatment regimen. Conclusion: A chronic health condition may likely place the adolescent in jeopardy for developing emotional and behavioural problems which may hinder adherence to treatment regimen. Also, the functioning of the family in which the adolescent resides can influence adherence to the diabetes regimen.