There are a large variety of nickel alloys mainly because nickel is able to dissolve a large amount of alloying elements while maintaining a single ductile phase. Nickel alloys are generally designed and used in highly aggressive environments for example when stainless steels may not perform well. Nickel alloys are generally resistant to pitting corrosion but are prone to crevice corrosion attack. A critical review will be presented for each family of nickel alloys both from the controlled laboratory research point of view and from the field performance perspective.