The article describes the combined effects of grain size and second phase particles on mechanical properties of CuCrZr alloy subjected to SPD processing and ageing in two sequences: (i) SPD processing followed by ageing and (ii) SPD processing of samples aged prior to deformation. It was revealed that each of these strengthening mechanisms acting alone gives a significant increase in mechanical strength (5 and 10 times in the case of ageing and SPD processing, respectively). However, it has been found in the present study that the strength of samples subjected to grain refinement and precipitation hardening is not a direct sum of the strengthening brought about by these two strengthening mechanisms acting alone. This finding is discussed in terms of the inter-dependence of grain size-particle strengthening in SPD nano-metals.