Constant amplitude fatigue crack propagation rate (da/dN) data are provided for several aluminium alloys commonly used in the aerospace industry, in the form of plate, extruded bar and forgings. The data have been derived from tests conducted in laboratory air at room temperature and mean da/dN curves are presented in terms of the stress intensity factor range and the stress ratio. Where possible curves representing the upper limit of 95 per cent of the data are also provided. Values for the coefficient and exponent in the Paris equation are tabulated for ranges of crack growth rate and fixed stress ratio. The ranges of da/dN covered are from 1E-3 m/cycle (3.9E-2 in/cycle) down to the fatigue threshold stress intensity factor range, at 1E-11 m/cycle (3.9E-10 in/cycle) . The effects of variations in the stress ratio, test piece thickness, grain flow and environment are discussed. Details of all the alloys and types of test pieces are tabulated and summary da/dN curves that compare the performance of the different alloys are given. Curves showing the effect of variations in the value of stress ratio at threshold for the various alloys are also presented. A simple worked example illustrates how the data may be used in practice.