Transactions are crucial to ensuring the quality (such as recovery and reliability) of web services applications by constraining them to a mutually agreed outcome. This paper addresses the issue of testing the long-lived web services transactions which has been given little attention by the current research. It proposes a risk-based approach and also defines a set of properties for web services transactions. The proposed approach identifies for each property a set of potential situations that must be tested. We present an analysis for the Recovery property using a Fault Tree diagram where the leaf nodes represent potentially dangerous scenarios that must be checked. Finally we show with a case study how this Fault Tree can be used to derive test cases for web services transactions.