TSNAs in air-cured tobacco can be lowered by reducing the specific alkaloid precursor, by manipulating curing conditions, or by reducing total alkaloids. The most effective TSNA reduction strategy to date has been to reduce nornicotine, the precursor of the major Burley TSNA, NNN (N'nitrosonornicotine), by seed screening. Curing conditions are known to have a major impact on TSNA accumulation, but manipulation of curing has not been a successful strategy because of the difficulty of maintaining acceptable leaf quality. Many studies have shown that TSNA accumulation can be reduced by any practice which lowers total alkaloids, such as lower nitrogen fertilizer rates. However, if the TSNAs decrease at the same rate as the alkaloids, or at a lower rate, the benefit is questionable. The objective of this study vas to establish whether reducing alkaloids results in reduced TSNAs per unit of alkaloid as well as in reduced absolute amounts of TSNA. In a two-year study, high and low converter lines were grown with standard and zero nitrogen rates. Cured leaf was analyzed for alkaloids and TSNAs. TSNAs increased exponentially as total alkaloids increased, on both a weight basis and on an equivalent basis. TSNAs were reduced in the zero nitrogen treatment, whether they were expressed as an absolute amount or per unit of alkaloid. This suggests that when alkaloids are reduced by lowering nitrogen rates, TSNAs are reduced to a greater extent. TSNAs relative to total alkaloids were reduced to a greater extent by the low converter line than by the zero nitrogen treatment.