Scale samples and length and weight measurements of 281 pike from Great Bear lake, Great Slave lake, lake Athabaska and Lesser Slave lake have been used to calculate the rate of growth. A comparison with the growth rate of pike from Waskesiu lake, Saskatchewan, and lakes in Wisconsin shows that, in general, the rate varies with north latitude. The northern fish live five years longer but never attain as large a size. It is shown that the relationship between length and weight is independent of the rate of growth. Males and females grow at the same rate but females appear to live longer than males.