Expert readers use a lexical and an analytical procedures to identify written words (Ans et al., 1998; Coltheart et al., 2001). Experimental data suggest that beginning readers develop their alphabetic and lexical knowledge simultaneously (Martinet et al., 2004). This is in primary school that these mechanisms must be installed and their automatisation promoted. However, in France, more than 14% of students entering middle school present difficulties in written words identification; difficulties that can impedes access to the meaning of a text (Hoover & Gough, 1990). The objective of our research is to evaluate the effectiveness of instructional intervention to help eliminate proportion of reading difficulties due to poor written-word identification abilities and to compare the effectiveness of such program in schools of different areas. In our study, written word identification performance (number of words correctly read in one minute) of students from 12 primary schools (half were schools targeted for special help) was evaluated at the beginning of school year with the ELFE (2nd to 4th graders) or ROC protocol (5th graders) (Cognisciences). For the 408 students evaluated as having reading difficulties, a syllable and pseudoword (2nd graders) or a sentence (other graders) dictation test were used to decide whether a student should be given training focusing on decoding or on building/constructing his orthographic lexicon (fluency). The remediation program for students with decoding difficulties was based on “Imprégnation Syllabique” (Garnier-Lasek, 2002), a method for consolidating decoding skills based on syllables, rather than phonemes (Magnan et al., 2010). For students who correctly decoded words but had difficulties with automating written-word identification, remediation training was based on fluency using repeated-reading techniques (Lequette et al., 2011). At the end of the school year, written-word identification was re-evaluated. Progress in reading obtained for the children that followed our program was compared to those of students matched on school level that did not follow the program. Independently of the nature of the training session, the increase was greater for students that follow our program compared to those who didn't, but this increase was found less important for children from disadvantaged (“education prioritaire”) areas.