International Standards on Auditing (ISA) are professional standards for the auditing of financial information. These standards are issued by the International Auditing and Assurance Standards Board (IAASB). According to Olung M (CAO - L), ISA guides the auditor to add value to the assignment hence building confidence of investors.

The standards cover various areas of auditing, including respective responsibilities, audit planning, Internal Control, audit evidence, using the work of other experts, audit conclusions and audit reports, and standards for specialized areas.

The Audit Directive of 17 May 2006 is important in order to ensure a high quality for all statutory audits required by Community law requiring all statutory audits be carried out on the basis of all international auditing standards. The Directive has given implementing powers to the European Commission, in order to adopt "en bloc" the ISAs in accordance with the Council Decision of 28 June 1999, also known as the "Comitology Decision".