Orthographic knowledge can be regarded as stored information about the
regularities and exceptionalities of the spelling system, and orthogr
aphic processing skill as the ability to use such information efficien
tly in a range of reading and spelling tasks. This paper focuses on th
e role of orthographic processing skill in adults' reading proficiency
. A case study is discussed in which orthographic processing skill. wa
s perfected despite phonological deficiencies, allowing highly skilled
silent reading. Data are also presented which indicate that orthograp
hic skill plays a significant independent role in fluent reading aloud
of connected text. The importance of studying the various aspects of
orthographic processing capability and their contribution to the proce
ss of attaining adequate literacy competence is stressed.