The Global Initiative for Asthma (GINA) guidelines stated the therapeutic goals for the management of asthma and, through a stepwise approach to treatment, defined the various grades of asthma severity and the therapeutic options available to the clinician at each step. This article considers the options at step 3; the management of a patient with poorly controlled asthma who is already taking low-dose inhaled corticosteroids.Before considering a change in therapy, the clinician should rule out alternative diagnoses, confirm compliance with treatment, explore potential exacerbants in the patient's environment and, where possible, remove them. If a change in medication is necessary, the choice of drug will depend on the therapeutic goal that needs to be achieved. If the most important goal is the control of symptoms and optimisation of lung function, most studies support the addition of a long-acting β2-agonist to low dose inhaled corticosteroids. If recurrent severe exacerbations are a major feature of the poor control, increasing the dosage of inhaled corticosteroids may be most effective. The addition of a leukotriene antagonist may be the best choice if exercise-induced symptoms are prominent or in the setting of aspirin-sensitive asthma.General recommendations supported by the findings of large therapeutic trials do not allow for significant variability in the individual response to a particular drug. Receptor polymorphisms have recently been discovered that may account for variability in the response to β2-agonists and leukotriene receptor antagonists. However, until more is known about the reasons behind this variability, a therapeutic trial may be the most effective way of determining the best drug for an individual patient.One of the key developments in asthma over the past decade has been the acceptance of the concept of asthma as a chronic inflammatory disorder of the airways. However, the long term significance of this inflammation is not clear and the importance of control of inflammation beyond the suppression of symptoms, reduction of exacerbation frequency and the optimisation of lung function has not been established.