The sperm content of the spermatheca was examined in eleven species of yellowjacket queens collected in the spring of 1987–1989. The sperm count data were highly correlated (r= 0.84) with total cell numbers of mature nests reported for 10 species. Sperm content varied within and among species with mean numbers of sperm ranging from a low of 3,200 ± 600 inVespula consobrinain 1988, to a high of 176,000 ± 46,200 inVespula squamosa, the same year. The implications of mating success and initial sperm quantity variability are discussed.