A thorough understanding of the cognitive effects of corticosteroids is essential given their frequency of use. This meta-analysis was conducted to investigate the effects of corticosteroids on the various domains of cognitive functioning, grouped by duration of use. An electronic search of PsycInfo, Medline and Google Scholar was conducted for all journal articles published between January 1990 and May 2018. Twenty six studies were included enabling calculation of standardised mean difference (SMD) using a random effects model for the cognitive domains of divided attention, executive function, expressive language, immediate memory, processing speed, recent memory, sustained attention, very long term memory and working memory. Results revealed that corticosteroids had a modest, negative effect on executive function for acute users, recent memory for short term and chronic users, and very long term memory for acute users. Corticosteroids had a small, significant, positive effect on expressive language for short term users.