The auditors, recognized for their high technicality and their decision-making abilities, are called upon to play a very important role in the presentation of the accounting figures produced by company managers. They are supposed to report with independence, objectivity and integrity. However, recent financial scandals, not only in large American and European firms, but also in Africa and particularly in Cameroon, have called into question the trust once placed in the auditors of accounting figures. This paper aims to examine the effects of the institutional environment on the behaviour of controllers of accounting figures. Based on a final sample of 146 Cameroonian SMEs, it is found that the fiscal environment through the finance law, tax pressure and auditor's fees on the one hand, and the legal environment through auditing standards and institutional sanctions on the other, have a positive impact on the behaviour of the auditor of accounting figures.