This paper examines the main orthographic innovations of the early Islamic orthography in comparison to the Nabataean orthography and traces through new epigraphic evidence when and where these innovations came to be used. It is shown that a number of them clearly develop already in the pre-Islamic period. Besides this, the paper looks at the complexities of Arabic orthography and morphophonological spelling as it is reflected in the Quranic orthography as well as pre-Islamic inscriptions and argues that the early Islamic orthography represents the continuation of a developed Hijazi scribal tradition.