Targeted drug delivery is a method of delivering bioactive compounds to a patient in a manner that increases the therapeutic index. The main goal of a targeted drug delivery system is to prolong, localize, target and have a protected drug interaction with the diseased tissue. Antibody-drug conjugates (ADC) represent an innovative therapeutic application that combines the unique properties of monoclonal antibodies with the potent cell killing activity of cytotoxic bioactive compounds. ADCs are complex molecules composed of an antibody linked, via a stable, chemical, linker with labile bonds, to a biological active cytotoxic (anticancer) payload or drug. The key components of ADC include a monoclonal antibody, a stable linker and a cytotoxic agent to target a variety of cancers. The present mini-review deals with the examination of clinical use and pharmacological properties, as well as the safety of antibody-drug conjugates that are marketed. Ado-trastuzumab emtasine and brenduximab vedotin were examined regarding their mechanism of action, pharmacology, clinical use and safety. These ADCs selectively deliver cargoes to tumor cells and provide clinical benefit by minimizing systemic toxicity.