The dominant error types were investigated as a function of phonological processing (PP) deficit severity in four groups of impaired readers. For this aim, an error analysis paradigm distinguishing between four error types was used. The findings revealed that the different types of impaired readers were characterized by differing predominant error types. The dysphonetic errors predominated in readers with severe PP deficit and the morphological errors predominated in those with moderate deficits. Finally, readers with attention difficulties showed a predominance of semiphonetic errors. These findings were discussed in relation to reading disability subtypes and their clinical implications.