Let a be a fixed-point-free automorphism of order rs of a finite group G, where r and s are distinct primes. In the present paper a condition for the s-th power of σ to fix a unique p-Sylow subgroup of G, for every prime p dividing the order of G, is given. A similar condition for such a s-th. power to fix a unique p-Sylow subgroup is also obtained for the case of a solvable group, when σ is of any order.