We studied the relationship between the intensity of dyspnea and psychopathological and personality dimensions in 74 women and 38 men (mean age 49.7 years) with asthma. The women had higher values for the following variables: depression, anxiety-trait, and neuroticism, and they proved to have a greater external control location than the men. After checking the spirometry results, body mass index (BMI) and gender, it was found that dyspnea correlated with anxiety-trait and anxiety-state, neuroticism, and depression. In the men, anxiety-trait modified the relationship between dyspnea and the duration of the disease. This effect was not found in the women. A high level of anxiety-trait seems to be responsible for the escalation of dyspnea during the progression of the disease in men, whereas low anxiety may protect them against the increase of dyspnea. FEV(1), BMI, and anxiety-trait were predictors of dyspnea.