More research is needed to further our understanding of posttraumatic stress disorder symptoms (PTSD) and psychiatric co-morbidity following stroke, especially the trajectories of such symptoms over time. Previous studies suggest that exposure to a traumatic experience such as stroke is not sufficient to explain the etiology of PTSD. Alexithymia may be involved, but its relationships with PTSD and psychiatric co-morbidity following stroke remains unclear. This study aims to address these knowledge gaps. While in hospital, stroke patients (n = 90) completed questionnaires assessing PTSD symptoms, psychiatric co-morbidity, alexithymia and physical disability. PTSD symptoms and psychiatric co-morbidity were re-assessed approximately 3. months post-stroke (n = 78). The severity of post-stroke PTSD did not change significantly over time, while psychiatric co-morbidity reduced significantly. Alexithymia, in particular difficulty in identifying feelings, was associated with severity of post-stroke PTSD and psychiatric co-morbidity at baseline, but after adjusting for these, there was no significance 3. months post-stroke. We suggest that patients' difficulty in identifying feelings had a role to play in influencing relatively short-term rather than long-term PTSD and co-morbid psychiatric symptoms. Alternatively, PTSD could be interpreted as driving the alexithymic characteristics. © 2010 Elsevier Ltd.