Deco Proteste is Portugal's largest consumer rights organization, providing independent product testing, legal advice, dispute mediation, and advocacy on behalf of consumers. It is part of the international Euroconsumers group.

Deco publishes comparative tests of products and services (from insurance policies to supermarket prices), lobbies for consumer-friendly legislation, and runs a mediation service that helps resolve disputes between consumers and companies. It also operates helplines during crises — such as severe weather events — to advise on insurance claims, billing disputes, and emergency consumer rights.

Membership is paid, but Deco's public advocacy and media presence make it a significant voice in Portuguese consumer affairs. Its studies and reports are frequently cited in news coverage of cost-of-living, energy prices, and financial products.