The pharmacologic treatment of chronic obstructive pulmonary disease (COPD) differs from that of asthma in several respects. Oral therapy should be the keystone, using a long-acting theophylline or a beta 2-sympathomimetic agent. The addition of a metered dose inhalant aerosol provides additive benefit with low toxicity; either a sympathomimetic agent or ipratropium or both should be used. The antiinflammatory aerosols, cromolyn, and steroid drugs are usually of no value, and oral steroids are only indicated if there is an asthmatic component. Mucokinetic agents and antibiotics should be used selectively. The numerous other drugs that may be required by a COPD patient must be prescribed with consideration to the potential for adverse physiologic effects and untoward drug interactions.