Characterization of creep-dominated fatigue cracking or cavitation in smooth specimens of a type 304 stainless steel is emphasized in terms of the stochastic nature of small-crack initiation and growth. As compared with monometallic ductile steels, a somewhat different cracking behaviour is shown for a titanium alloy Ti-17, an oxide-dispersion-strengthened nickel-base superalloy Inconel MA754 and a grey cast iron FC25. The mechanical behaviour of the large-crack propagation of creep and high temperature fatigue in high strength, low ductility materials is discussed in comparison with ductile materials. A quasi-small-scale creep condition dominates for the creep-fatigue crack propagation of the nickel-base superalloy Inconel 718, and a pure small-scale creep condition is established in the creep crack propagation of an aluminium alloy 2014-T6 and a carbon-fibre-reinforced polymer, namely unidirectional carbon fibres-poly(ether-ether-ketone) composite.