Whistleblowing, which is the disclosure by an employee of irregularities occurring in their organization, plays a vital role in combatting wrongdoings in public institutions and business. The article discusses the key questions relating to whistleblowing and its social significance. It indicates the crucial problems connected with the disclosure of irregularities and social reactions to whistleblowing. The article refers to R.K. Merton’s concept of non-conformity and to the positive social deviance theory. The issues discussed are illustrated by recent Polish examples of whistleblowing.