Background For the majority of chronic asthmatics, symptoms are best controlled using inhaled steroids, but for a small group of asthma sufferers, symptoms cannot be controlled using inhaled steroids and instead continuous use of high dosage oral steroids (corticosteroids) are required. However, using high dosage oral steroids for long periods is associated with severe side effects. Steroid-sparing treatments have been sought and one of these is chloroquine. Chloroquine is an anti-inflammatory agent, also used in the treatment of malarial infection and as a second-line therapy in the treatment of rheumatoid arthritis, sarcoidosis and systemic lupus erythematosus. All these diseases are associated with immunologic abnormalities hence the speculation that chloroquine might be used to control severe, poorly controlled bronchial asthma. There is a need to systematically evaluate the evidence regarding its use to reduce or eliminate oral corticosteroid use in asthma. Objectives The object of this review was to assess the efficacy of adding chloroquine to oral corticosteroids in patients with chronic asthma who are dependent on oral corticosteroids with the intention of minimising or eventually eliminating the use of these oral steroids. Search methods Searches of the Cochrane Airways Group Specialised Register were undertaken with predefined search terms. Searches are current as of February 2011. Selection criteria Only studies with a randomised placebo-controlled design met the inclusion criteria for the review. Data collection and analysis Two reviewers independently assessed studies for suitable in the review. Data were extracted and entered into RevMan 5. Main results One small study was included in the review. No significant findings were reported. An update search conducted in February 2007 did not identify any new studies. Authors' conclusions There is insufficient evidence to support the use of chloroquine as an oral steroid-sparing agent in chronic asthma. Further trials should optimise oral steroid dosage before addition of the steroid-sparing agent.