Purpose: To investigate the nature and extent of oral language difficulties encountered by adults who are functionally illiterate. Method: Fifty-two men and women identified as functionally illiterate, together with a group of control individuals of comparable age, sex, and socioprofessional background, produced a narrative intended for an absent recipient based on a sequence of pictures featuring a cast of 3 protagonists. All narratives were transcribed in their entirety and coded in terms of linguistic features and discourse organization. Results: As a group, the participants who were illiterate had great difficulty handling morphosyntactic rules, referential cohesion, and the narrative schema. Furthermore, a qualitative analysis highlighted considerable interindividual variability in narrative styles, reflecting different types of difficulties. Conclusions: Individuals who have not succeeded in learning to read also have impaired oral language abilities. This may affect different aspects of communication skills to a greater or lesser extent. These results have implications for teaching written language to adult learners.