Chapter starts with indications and contraindications for amalgam Class I restoration. The chapter explains in length about class I outline form, retention form and resistance form preparation details. This is followed by insertion of amalgam section and about finishing of amalgam restoration. Occlusolingual cavity preparation in maxillary molars and other modifications of Class I preparation like facial pit preparation on mandibular molars are explained. This is followed by mentioning about Marzouk designs of Class I preparation. The chapter finishes off with explaining about features in a Class I preparation.