Quality of life may be significantly affected in type 1 Diabetes Mellitus subjects and seems to be highly related to depression, self-image, and everyday life of the diabetic individuals. Diabetes is a challenging disease because of its chronic nature, long-term complications and high demands for daily monitoring and care. It may be perceived as threatening to the extent that it interferes with social, physical, psychological or role functioning. The latter are the four primary domains of quality of life, which in clinical practice represents the functional effects of an illness and its consequent therapy upon a patient, as perceived by the patient. Thus, the management of diabetes is clearly a complex behavioral process, influenced by a multitude of disease, individual, psychosocial, situational and nutritional variables. In particular, demographic and health background variables, blood glucose levels (especially hypoglycemia – the major disadvantage to therapy), psychosocial parameters and attitudes towards diabetes were examined, in order to investigate their impact on various aspects of quality of life. The present study aimed at the evaluation of the quality of life (QoL) of Greek type 1 diabetic subjects. This research is a precursor of a project entitled: ‘Enhancement of Quality of Life in Type 1 Diabetic subjects’. Patients – Method: In sixty-nine participants with DM type 1 (32 men), aged 18-55 years, were administered QOLID-89 measuring QoL and functioning levels, SCL-90-R estimating psychopathology, ASI measuring the anxiety sensitivity in everyday life, BDI-II measuring possible depression and EDI evaluating nutritional habits and/or disorders as well as self-image of the diabetics. The statistical package SPSS v.12 was used for Pearson’s partial and multiple correlations. According to the results, patients with IDDM1 seem to face difficulties regarding the four primary domains of the health-related quality of life: The smaller the QOLID-89 scores, the more patients worry about their condition and the harder their everyday life becomes, since their social life, emotional well being, attention, and nutritional habits are affected, as well as the overall quality of life. In addition, self-reported symptoms of disturbed sleep have been found to correlate positively to pain, attention, concentration, memory, social isolation and overall quality of life. Furthermore, the subjective perception of quality of life was associated with problems the participants have in discussing their disease with other people. The fear of having hypoglycemic episodes and the disappointment from their own body image seem to affect patients’ well-being negatively.