Hydrocodone is an epoxy-methoxy-methylmorphinan semisynthetic opioid (6-deoxy-3-O-methyl-6-oxomorphine hydrogen tartrate hemipentahydrate), which is structurally related to codeine, and is classified as a step 2 opioid on the World Health Organization's stepladder for pain. Hydrocodone is typically found in fixed dose combination with acetaminophen and is often used for pain management. Hydrocodone is a heavily prescribed drug and it is important to understand the evidence base that is guiding this use. This article reviews the pharmacodynamics, pharmacology, and evidence base for the use of hydrocodone in palliative care.