Anelastic relaxations of amorphous Zr65Al7.5Cu27.5 have been studied in the range of the glass transition and in the supercooled liquid. Applying a force step function, an anelastic aftereffect of the form exp(t/τ)β (Kohlrausch–Williams–Watts function) is expected with an exponent β≪1. From the measurement a value of β=0.67±0.03 is determined at Tg which confirms the empirical correlation between the fragility index m (36.4 for Zr65Al7.5Cu27.5) and β, established by Böhmer et al. This result is another indication for the metallic glass Zr65Al7.5Cu27.5 being a rather strong glass former. Furthermore, a strong increase in β just above Tg is found and is interpreted in the framework of a cluster model. © 1996 American Institute of Physics.