HM Crown Prosecution Service Inspectorate (HMCPSI) inspects the work carried out by the CPS and some other prosecuting agencies. Its purpose is to enhance the quality of justice and make an assessment of prosecution services which improves their efficiency, effectiveness and fairness. HMCPSI also undertakes joint inspections with the other Criminal Justice Service (CJS) inspectorates which focus on broader issues across the CJS and collaborates with other inspectorates or public authorities.

HMCPSI works with the Attorney General's Office.