Epidural injection with corticosteroids is a common treatment option for patients with lower back pain or sciatica. In this paper we review its origin and evolution. The first injections were given around 1900 in Paris by Jean Sicard (1872-1929) and Fernand Cathelin (1873-1945), who worked independently. They both injected small volumes of cocaine into the sacral hiatus. After a slow start, the epidural treatment of back pain and sciatica gradually spread to other parts of Europe and Northern America. In the early 1950s, corticosteroids were introduced for epidural use. Since the 1970s, there have been numerous clinical trials that show a significant, although small, effect of epidural corticosteroid injections compared with placebo for leg pain in the short term. Despite an ongoing debate about effectiveness and safety, epidural injections remain popular.