Sampling is widely used in market research, scientific analysis, market analysis, opinion polls and not least in the financial statement audit. We wonder what is actually sampling and how did it appear? Audit sampling involves the application of audit procedures to less than 100% of items within an account balance or class of transactions. Nowadays the technique is indispensable, the economic entities operating with sophisticated computer systems and large amounts of data. Economic globalization and complexity of capital markets has made possible not only the harmonization of international accounting standards with the national ones, but also the convergence of international accounting and auditing standards with the American regulations. International Standard on Auditing 530 and Statement on Auditing Standard 39 are the two main international and American normalized referentials referring to audit sampling. This article discusses the origin of audit sampling, mentioning a brief history of the method and different definitions from literature review. The two standards are studied using Jaccard indicators in terms of the degree of similarity and dissimilarity concerning different issues. The Jaccard coefficient measures the degree of convergence of international auditing standards (ISA 530) and U.S. auditing standards (SAS 39). International auditing standards and American auditing standards, study the sampling problem, both regulations presenting common points with regard to accepted sampling techniques, factors influencing the audit sample, treatment of identified misstatements and the circumstances in which sampling is appropriate. The study shows that both standards agree on application of statistical and non-statistical sampling in auditing, that sampling is appropriate for tests of details and controls, the factors affecting audit sampling being audit risk, audit objectives and population\’s characteristics.