This study investigates the key determinants of the adoption of innovation (ISO 9000 standards). These determinants are classified into three groups of factors: first, the perceived characteristics of innovation, comprising perceived relative advantage, perceived complexity, perceived compatibility and observability. The second group, characteristics of the external environment, includes competitive pressure, environmental uncertainty, external pressure and external support, while the third group, organisational characteristics, involves management support, centralisation, formalisation and organisational size. For this purpose, an analysis was carried using data from 239 manufacturing companies operating in Egypt. The results show that characteristics of innovation, characteristics of the external environment and organisational characteristics are significantly associated with the adoption of ISO 9000 standards by manufacturing companies.