OBJECTIVES:  Evidence suggests that current levels of adherence to diabetes management strategies (drug therapy, self-monitoring of blood glucose and life style recommendations) are alarmingly low. This analysis aims to estimate the economic value and the clinical impact of sequential increases in the level of adherence to diabetes treatment among patients with Type 2 diabetes in Spain. METHODS:  Clinical and economic outcomes were calculated based on data derived from published sources. These include how adherence variations do impact glycosylated hemoglobin levels (HbA1c) and how HbA1c variations do impact diabetes related complications. Inputs also included the estimated current adherence level to diabetes treatment, number of patients with Type 2 diabetes in Spain, and costs and rates for 7 parameters: complications related to diabetes, death related to diabetes, all-cause mortality for patients with Type 2 diabetes, myocardial infarction, stroke, amputation and cataract extraction. RESULTS:  Each 10% increase in the level of adherence to diabetes treatment could potentially translate into a 2.8% risk reduction in complications related to diabetes. If the current 45% non-adherent patients in Spain would fully adhere to diabetes treatment, the risks of complications and death due to diabetes would be reduced by 29% and 21% respectively. Considering there are approximately 1,609,000 non-adherent patients with type 2 diabetes in Spain, the potential annual total costs savings would exceed 128€ million, which equal 2.2% of total Spanish diabetes expenditure. CONCLUSIONS:  The benefits of drug therapy in diabetes in terms of glycemic control and complication reduction have been well established in the literature. However, without regular and compliant use of medication, therapy benefits would be tremendously reduced. It is, therefore, critical to undertake effective strategies aimed at improving patient adherence to diabetes treatment. The results of this analysis might encourage public authorities and HCPs to commit and implement strategies to improve patient adherence.