This book fills an important gap in the literature on European sales law, where sales law is a much-studied object for legal comparatists, while, at the same time, comprehensive analysis of sales guarantees is largely missing. The book constitutes one of the key results of a large scale research project conducted under the auspices of the Study Group on a European Civil Code and, thus, can be seen as the work underlying the provisions on guarantees of the Principles of European Law on Sales (PELS) and the Draft Common Frame of Reference (DCFR). The book provides an exhaustive analysis of the legal phenomenon of the consumer guarantee, disclosing the competition law roots of the legislation regarding this - the effects of the Unfair Contract Terms Directive and the Consumer Sales Directive. Furthermore, the book looks at the solutions adopted in the Consumer Sales Directive, and it questions their effectiveness. It is recommended reading for academics and practitioners working in the field of consumer guarantee legislation.