OBJECTIVE: To evaluate glycemic control, hypoglycemic events, and quality of life in patients treated with continuous subcutaneous insulin infusion (CSII) and multiple daily insulin injection (MDI), with insulin lispro as the principal insulin. RESEARCH DESIGN AND METHODS: This clinical trial enrolled 27 patients with type 1 diabetes. They were randomly assigned to CSII (n = 13) or MDI (n = 14) treatment regimens. Glycemic control (HbA(1c) level) was the primary outcome and was measured monthly for 9 months. Secondary outcomes were patient reports of hypoglycemic events (recorded monthly for 9 months) and quality of life assessed at 9 months using the Diabetes Quality of Life (DQOL) questionnaire. RESULTS: A significant decrease in HbA(1c) from baseline was shown for both groups. However, the overall treatment effect (CSII - MDI) for HbA(1c) was +0.08% (95% CI -0.23 to +0.39, P > 0.10). This was significantly less than the a priori limit of +/-0.5% (P = 0.004). The relative treatment effect ([CSII - MDI]/MDI) for the overall number of hypoglycemic events was +9% (95% CI -37 to +87, P > 0.10). There were no statistically significant differences between treatment groups for any of the DQOL subscales. CONCLUSIONS: No statistically significant differences in glycemic control, reported hypoglycemic events, or quality of life were found in this study. Furthermore, a clinically significant difference of more than +/-0.5% HbA(1c) between the two regimens can be confidently ruled out. We conclude that the choice of intensive insulin therapy should be a matter of patient preference, consistent with lifestyle.