BACKGROUND Although the existence of classical occupational asthma is well known and described after fairly prolonged exposure to moderate levels of air-contaminators, authentic asthma can be provoked by rapid single inhalation of a high dosed corrosive gas: this is Brooks' syndrome. METHODS A 30 year-old woman, without respiratory past history and no atopy presented with post-toxic asthma following a single accidental inhalation of hydrochloric acid. The diagnosis was established on the 8 criteria of Brooks and the clinical outcome remained stable with, however, excellent response to the inhalation of broncho-dilatators during asthma attacks. CONCLUSIONS The relationship with the accidental inhalation may have been ignored by the victim. The outcome of this syndrome is good in 50% of cases; in 25% the symptomatology worsens and in the remaining 25% it remains stable.