Objective: To update current evidence on the cost-effectiveness (CE) of therapeutic education in prediabetes and type 2 diabetes. Research design and methods: A systematic review of economic evaluations of therapeutic education in prediabetes and type 2 diabetes, based on Randomized Controlled Trials (RCTs) and published in 2002 - 2014. The quality of the clinical evidence was appraised through the Cochrane Collaboration’s tool for assessing risk of bias. Economic studies were evaluated through the Consensus Health Economic Criteria List. The Incremental Cost- Effectiveness Ratios (ICERs) of patient education in prediabetes and type 2 diabetes were compared. Results: Out of 2031 identified publications, eight studies on prediabetes and nine on type 2 diabetes met the inclusion criteria. The level of the underlying clinical evidence was overall high in studies on prediabetes and varied in studies on type 2 diabetes. The mean ICER (95% CI) from the perspective of the healthcare system was €18,000 per QALY (range from dominance to €49,700) in prediabetes and €29,700 (range from €9,100 to €50,300) per QALY in type 2 diabetes. General flaws in the economic evaluations were short time horizons, limited uncertainty analysis and a lack of transparency in the modeling methods. Conclusions: The number of economic evaluations of patient education in prediabetes and type 2 diabetes has been growing in the past years. Our review compares the health economic evidence on therapeutic education for both conditions. The findings suggest that offering therapeutic education already in prediabetes stage may be a better value for money than postponing it till after the diagnosis. More robust methodologies in health economic evaluations are essential in further evidence generation.