Background: ‘Functional relaxation’ (FR) according to Marianne Fuchs is a body-oriented psychotherapy that involves teaching the patient a type of relaxation techniques aimed at maintaining equilibrium of the nervous system. Methods: In order to determine whether the practice of elementary parts of this therapy has an immediate beneficial effect on pulmonary function, a randomized, single-blind, prospective crossover study was done with 21 asthmatics with acute bronchoconstriction. On 3 consecutive days they were given either (1) a 5-min verbal standard instruction in elementary exercises of FR (eFR), which they were to practice during subsequent bodyplethysmographic measurement or (2) inhalative terbutaline (IT), a β2-sympathomimetic drug, or (3) an unspecific ‘placebo relaxation’ technique (PRT), so that all subjects tried all 3 treatments in random order. Spirometric variables were assessed. Results: There was a significant decrease in specific airway resistance with eFR, which, though not as pronounced as with IT, was significantly greater than with PRT. This study shows that clinically relevant effects can be achieved for patients with asthma through mind-body interaction, which can be triggered by reproducible procedures. Conclusion: Further development of the FR approach could lead to a nonpharmacological and effective supplementary treatment for asthma, which is in high demand by many patients.