A simple peptide based prodrug of camptothecin (CPT) has been synthesised in which the CPT is conjugated to a tripeptide (KCK) via a disulfide linkage (KCK-CPT) and self-assembled into well-defined nanostructures in water depending on the concentration. The hyaluronic acid (HA) complex of KCK-CPT exhibited target specific toxicity with excellent antitumour efficiency.