In a previous study of a group of 74 patients with Type I diabetes, quality of life was found to be consistently enhanced a year after transition to multiple injection therapy with the insulin pen, whereas metabolic control (HbA1C) only improved moderately. The aim of the present investigation was to examine quality of life, recent life events, and metabolic control longitudinally in this original study group over a 5-year period beginning 1 year after transition to the insulin pen. Multiple analysis of variance with a repeated-measures design was used to analyze the data longitudinally and compare metabolic control in subgroups of well-controlled and poorly regulated patients during the study period. For the group as a whole, quality of life was found to change only moderately, whereas metabolic control deteriorated significantly across time following transition to the insulin pen. The two subgroups exhibited distinct differences, however, in quality of life, recent life events, and metabolic control patterns. These findings are discussed in terms of the clinical suitability of a multiple injection regimen.