We investigated the spelling of derivational and inflectional suffixes by 10-13-year-old Greek children. Twenty children with dyslexia (DYS), 20 spelling-level-matched (SA) and 20 age-matched (CA) children spelled adjectives, nouns, and verbs in dictated word pairs and sentences. Children spelled nouns and verbs more accurately than adjectives and inflections more accurately than derivational suffixes. DYS children performed worse than CA in all cases and worse than SA in verb inflections, but similar to SA in all the remaining cases, consistent with a delayed rather than deviant performance pattern. Qualitative analysis showed that uncommon vowel graphemes were often replaced by more common patterns. Children with dyslexia may have weaknesses in grasping morphological information and/or in applying this knowledge to spell word suffixes.