This study examined the levels of posttraumatic stress disorder (PTSD) following asthma attack (post-asthma attack PTSD) and psychiatric co-morbidity among college students. It also investigated the association between these variables and alexithymia. One hundred and six college students participated in the study and completed an on-line survey comprising the Asthma Symptom Checklist, PTSD Checklist, General Health Questionnaire-28 and Toronto Alexithymia Scale. Ninety-one students without asthma and major illness formed the control group. 2 % met the diagnostic criteria for full-PTSD, while 42 and 56 % met the partial and no-PTSD criteria respectively. Compared with the control, the asthma group reported significantly more somatic problems, social dysfunction and depression and was five times more likely to have an elevated risk of developing a general psychiatric disorder. After adjusting age, marital status, asthma experience and symptoms, alexithymia did not predict PTSD, while difficulty identifying feelings predicted psychiatric co-morbidity. Mediational analyses showed that asthma symptoms partially mediated the link between difficulty identifying feelings and psychiatric co-morbidity. People can develop PTSD symptoms and other psychological difficulties following asthma attack. Alexithymia influenced general psychological difficulties independently of PTSD symptoms. © 2012 Springer Science+Business Media New York.