Inhaled corticosteroids (ICS) are common medications, used in respiratory medicine for controlling conditions such as asthma and other obstructive airway diseases. The systemic effects of oral corticosteroids are well known and established; inhaled steroids have been known to cause relatively minor and localized adverse effects such as oral candidiasis. However, less attention has been paid to their systemic effects. Although currently there is a paucity of prospective studies demonstrating the systemic effects of inhaled corticosteroids, there are numerous retrospective studies adding evidence to this link. Inhaled corticosteroids can affect the hypothalamo-pituitary-adrenal axis, bone density and growth, eyes, skin and immunity including an increased risk of pneumonia. Clinicians are recommended to aim for the lowest possible dose to avoid these systemic side effects. Fluticasone is more likely to cause systemic effects compared to budesonide. Newer ICS molecules such as ciclesonide may be more beneficial in reducing such systemic complications on prolonged use. This paper provides an updated overview of the common systemic effects encountered with ICS treatment.