Exploratory Testing (ET) is a software testing practice characterized by simultaneous activities: test design, test execution and learning from the test results. Recently ET has received much attention from testing practitioners and researchers as well as software testing standardization bodies. Nevertheless, scientific evidence and knowledge about ET’s application in software industry are little. This multi case study conducted in three software companies, provides insights into the real perception of Exploratory Testing and the role of this practice in the whole testing process of them. This study identifies three distinct applications of Exploratory Testing in these software companies: ET as a standard process; ET as a discretionary, formalized process; ET as an informal, ad hoc process. Also, a number of key factors that affect the choice of Exploratory Testing in an organization have been identified: product characteristics and features; the products market; pressure for faster product release.