Gammalloys generate numerous microstructures that sensitively depend on alloy composition, solidification path, processing route (casting vs.. wrought), post-processing heat treatment cycle and aging/stabilization. Their mechanical behavior varies widely dependent on the microstructure type as well as its detailed features, including phase distribution. The microstructures can be grouped into four typical groups: duplex, nearly lamellar (NL), fully lamellar (FL) and XD lamellar (XDL). The first three can be produced in cast as well as wrought forms, while XDL is in cast forms only, and their microstructure-property relationships are too complex to be quantified. However, the properties (tensile, fracture, creep, fatigue, DKth) of well-controlled wrought duplex and wrought FL materials can be described at least semi-quantitatively as a function of microstructure. Since other microstructure types are mixtures or variations of the two typical microstructures, the relationships can be estimated to predict their properties. The above interrelations will be assessed and discussed.