RESUMEN
This study examined the importance of morphological knowledge in the reading comprehension difficulties of poor comprehenders reading in a highly agglutinative language, Turkish. Participants were 56 students recruited from the second and third grades. In the assessment process, we applied three experimental paradigms addressing the participants' morphological and morpho-syntactical knowledge at the lexical and the supralexical levels. Data were collected in individual sessions and analyzed by running a series of GLM ANOVAs and calculating the Spearman-Brown correlation coefficient. Findings suggest morphological knowledge is an important indicator of reading comprehension difficulties in Turkish, a highly agglutinative language. The acquisition of adequate reading comprehension seems to be modified by particularities of the morphological knowledge.