The genetic structure of 41 Canadian populations (27 populations from British Columbia, two of which were from east of the Continental Divide, and the remaining 14 representing localities east of the Continental Divide) of the white pine weevil, Pissodes strobi (Peck), was investigated using isozyme markers. Differentiation among populations (F_ST) was estimated to be 0.084 and inbreeding within populations was low with estimated mean F_IS of 0.011. Although overall genetic uniformity among the studied 41 populations was high (mean Nei’s genetic distance = 0.027), differences among groups of populations were revealed in cluster analyses. The 16 weevil populations obtained from areas east of the Continental Divide formed a significant cluster with the 11 populations collected from the Interior British Columbia. The 11 weevil populations examined from the South Coast–Vancouver Island of British Columbia were distinct from this cluster, as were the three weevil populations collected from the North–Central Coast of British Columbia. Populations within the South Coast–Vancouver Island group were the most genetically dissimiliar to each other, with Nei’s genetic distance ranging from 0.004 to 0.108. This was caused, in part, by differences in allele frequencies in the Bella Coola, Eve River, and Nanaimo populations relative to the other eight populations within this group. Genetic diversity estimates, in terms of the mean number of alleles per locus, the percentage of polymorphic loci and the mean expected and observed heterozygosity, were higher in eastern than western populations.