Nine strategies for detecting and preventing welfare fraud are described, including data-matching, public tip-offs, media campaigns, stepped-up investigations, and recovery action. There is a detailed examination of prevention strategies that have been introduced progressively in Australia over the last three decades. Increased efforts to combat welfare fraud can be more effective in detecting and stopping existing fraud (secondary prevention) than attempting to prevent the initial onset of fraud (primary prevention). In theory, prosecutions might increase for a period after detection and prevention initiatives are introduced, but then the number should decline as the system matures. Data-matching as a means of detecting welfare fraud involves ensuring that information about a customer held by an income-support agency is consistent with that held by other agencies. Centrelink's current data-matching program involves the Australian Taxation Office, the Department of Veterans' Affairs, and Centrelink. Centrelink's electronic Tip-off Recording System was introduced in 1998, and a toll-free telephone number was introduced in 2005. In 2005, Centrelink began a 4-year media campaign, which encouraged customers to report changes in their circumstances that might influence their entitlements. Overall, the delivery of welfare payments and the prevention of fraud involve a difficult balancing act. On the one hand, there are obligations to protect customers' privacy, provide speedy delivery of benefits, and avoid additional hardship to customers through investigation and debt-recovery action. On the other hand, there is a legal and ethical duty to ensure that taxpayers' dollars go to eligible recipients. An examination of Centrelink's current prevention strategies indicates that the current approach is having a significant impact on secondary prevention, i.e., detecting fraud and stopping its continuation, as well as the recovery of losses that result from fraud. 1 table and 29 references