The children had nightmares, difficulty sleeping and were described as jumpy and on the edge.
Authors say, the mental health needs of pre-school children caught up in terrifying events should be considered.
Study: Tots can suffer from PTSD
The study in the American Journal of Psychiatry reports this is similar to the rate seen in adults but most cases go unrecognized.
That's because it's difficult to make the psychiatric diagnoses in this age group since toddlers frequently lack the ability to talk about their feelings and experiences.
