A statewide sample of WWII ex-POWs (N = 442) responded to questionnaires that sampled current and past difficulties with PTSD-related symptoms; an incidence of serious difficulties with these symptoms of 56% was revealed. Retrospective reports of temporal patterns revealed no consistent patterns of symptom occurrence, but, rather, a waxing and waning of difficulties over the 40-year period. Unexpectedly, measures of severity of the POW experiences did not predict current symptomatology. Rank at time of capture, however, was consistently and strongly predictive of PTSD. It is suggested that PTSD is a highly persistent phenomenon and that both situation and person variables contribute to the development and maintenance of PTSD.