Ultra-fine grained metallic materials are characterized by higher mechanical properties comparing with their conventional equivalents. However increase in strength under static load is not always accompanied by improved fatigue behaviour. Previous investigations on submicrocrystalline RS442 aluminium alloy produced by plastic consolidation of rapidly solidified flakes in the extrusion process revealed increase in its high cycle fatigue bending strength caused by annealing at 450°C. The aim of present studies was to evaluate the influence of heat treatment – also precipitation hardening – on static mechanical properties (hardness, tensile and yield strength) and fatigue strength of the alloy determined in high cycle stress controlled bending tests. Correlation between microstructure, static mechanical properties and fatigue behaviour was analyzed too.