The chapter starts with explanation about complex restorations, various factors involved in complex restorations. Then the chapter next outlines the advantages, disadvantages and indications of pin retained amalgam restorations. Various types of pins and its properties and characteristics are explained elaborately. Pin placement, various designs of pins, factors influencing pin placement size of pins is discussed in length. This is followed by cavity preparation design for pin retained amalgam restoration; failures in pin retained restorations are discussed. The chapter finishes off with other forms of retentive features for complex amalgam restorations like horizontal pins, slots, etc.