This article analyses the adoption and characteristics of internal audit departments in Italian companies, in the light of recent changes in the economic and political environment following the big financial scandals which occurred both in Italy and abroad. The research framework is informed by new institutional theory, driving the definition of a conceptual model. The research approach comprises two steps: first, a preliminary in-depth case study to support the research design (assessment of relevant variables and questionnaire's construction); second, an extensive survey involving 364 Italian companies, with a response rate of 63%. The article highlights an actual diffusion of internal audit structures among Italian companies. Data collected show increasing attention towards internal audit activities, resources and competencies and highlight the relevance of isomorphic pressures in influencing companies' support of internal auditing.