Hole transport along isolated chains of two types of molecular wire -sigma-bonded silicon and pi-bond-conjugated carbon-are studied in this article, It is shown that mobilities well in excess Of 0.1 cm(2)/V s are achievable for both types of wire, with disorder in the backbone playing a decisive role in determining the magnitude of the mobility. It is concluded that values in excess of 1 cm(2)/V s should be realizable (even at room temperature) if the disorder can be reduced by either chemical or physical means.