Lactic acidosis is commonly associated with states of hypoxia and decreased tissue perfusion. Elevated lactic acid levels have also been observed in individuals who are not septic and who are normotensive, but who have received systemic adrenergic agonist therapy. This report presents two patients with acute asthma treated with very large doses of aerosolized and systemic salbutamol, who developed lactic acidosis despite normal systemic hemodynamics and adequate oxygenation. Lactic acidosis was clinically important because it contributed to respiratory failure in one patient, and complicated the assessment and management of acute, severe asthma in the other patient.