Pollen hoarding by the honey bee can be modified by selection. Two-way selection for honey bees that hoarded high and low levels of pollen in nucleus colonies was made for four generations. Two different lines of bees were produced in which high-line colonies hoarded significantly more pollen than low-line colonies. Rapid separation exhibited by the two lines suggests that the heritability of this trait is high (divergence h2 = 49.5 percent ± 20.3 percent). Genetic gains of the lines were asymmetrical in which substantial progress was made during high-line selection, while little, if any progress was made during low-line selection. Polygenic inheritance involving additive genes was suggested by the steady Improvement of the high line over the four generations of selection. Pollen-hoarding differences were confirmed in full-sized colonies when high and low full-sized colonies were monitored from July to October. High-line full-sized colonies averaged from two to 13 times as much hoarded pollen as the low-line full-sized colonies.