Glucocorticoids are widely used to suppress inflammation - especially in the acute phase - in several inflammatory and autoimmune rheumatologic diseases. Despite their efficacy, their long-term use or at high doses is associated with numerous well-characterised side effects. Hyperglycaemia or frank diabetes is one of the most common, as its prevalence is estimated between 10-20%. Its pathophysiology is mainly due to increased insulin resistance. In this review, we provide a practical guide on how to monitor patients who are started on glucocorticoids, and how to detect and manage steroid-induced hyperglycaemia or diabetes.