Supply and/or utilization of putrescine has been suggested to be a regulatory step in synthesis of the pyrrolidine moiety of nicotine. Objective of this investigation was to determine the influence of soil potassium on polyamine and alkaloid composition of green and cured burley tobacco. Field experiments were conducted during three different growing seasons. Leaf yields increased with potash addition. Leaf samples from low potash treatments contained less K than control samples, but the accumulation of Ca in the leaf was not changed. Potash treatments which resulted in less than 2% K in the leaf produced leaf with increased amounts of polyamines and the increase was mainly in the perchloric acid insoluble fraction. Putrescine and spermidine as a percentage of total polyamines in the perchloric insoluble fraction increased from 14 and 44% during vegetative growth to 78 and 84% in the cured leaf, whereas in the control plants this increase was from 15 and 20% to 61 and 75%, respectively. Delayed harvest after topping increased yields, alkaloids, and sometimes polyamines, but did not affect potassium accumulation. There was no significant correlation between polyamines or polyamine fractions and nicotine accumulation (Potassium, Calcium )