One of the basic facts of group theory is that each finite group contains a
Sylow p-subgroup for each prime p which divides the order of the group. In
this note we show that each vertex-transitive self-complementary graph has
an analogous property. As a consequence of this fact, we obtain that each
prime divisor p of the order of a vertex-transitive self-complementary grap
h satisfies the congruence p(m) = 1(mod 4), where p(m) is the highest power
of p which divides the order of the graph.