The purpose of this study was to review studies reporting on quality of life and treatment satisfaction of patients with diabetes mellitus being treated with long-acting insulin analogues. A systematic literature search was made of trials published between January 1, 2000 and June 28, 2007. Retrieved studies were analysed, using predefined inclusion criteria as well as methodological and quality aspects. Twelve studies were included, all of them dealing with insulin glargine as the trial drug or for comparison. With regard to treatment satisfaction, insulin glargine was superior in one head-to-head comparison with NPH (neutral protamine Hagedorn) and one head-to-head comparison with NPH as an add-on to oral glimepiride. There was no difference in comparisons with continuous subcutaneous insulin infusion (CSII), insulin aspart or exenatide. Regarding health related quality of life (HRQoL), insulin glargine was shown to be superior to rosiglitazone as an add-on to metformin and sulfonylurea. Again, there were no differences in comparisons with NPH, CSII or exenatide. There are only a limited number of high quality studies showing that insulin glargine is superior regarding treatment satisfaction and HRQoL of patients with diabetes mellitus. There are fewer publications with good evidence of patient-reported outcomes than those reporting well-established outcomes using HbA1c levels or the incidence of hypoglycaemia.