A good management of diabetes requires at the same time self-regulation behaviour and a balanced involvement of family components. This study’s aims were: understanding fear of injections and perceptions of family conflicts in preadolescents and adolescents with type 1 diabetes mellitus and their mothers, comparing their perceptions, and identifying the risk factors impacting patients’ quality of life. Participants were one hundred and two patients (Mean age = 14.63, SD = 2.43; age range = 10-19 years; Females = 52) and their mothers (Mean age = 46.94, SD = 6.2, age range = 27-63 years), who filled in self and proxy-report questionnaires. Twenty % of patients and 14.7% of their mothers reported clinical score for fear of self-injection and blood testing. Mothers reported higher fear of injecting and family conflicts compared with the patients. Age, fear of injecting and family conflicts impacted significantly on patients’ quality of life perceptions. Clinical consideration and recommendations are given basing on the empirical results.