Boron deficiency in cotton (Gossypium hirsutum L.) may be corrected with foliar or soil B applications, but a thorough economic analysis of soilversus foliar-applied B has not been done. The objectives of this study were to determine: (i) the profitability of foliar-applied B compared with soilapplied B in cotton production; (ii) the economic benefit to cotton producers of foliar-applied B with an adjuvant; (iii) the influence of soil pH and the buffering properties of the adjuvant on the economic effectiveness of foliar-applied B. Field experiments were conducted in 1993 through 1995 evaluating soil and foliar applications of B to cotton produced on a Collins silt loam soil (coarse-silty, mixed, active, acid, thermic Aquic Udifluvents). Foliar-applying B four times at a rate of 0.11 kg ha-1 per application was clearly more profitable than foliar-applying B at twice that rate. Foliar-applying B at the 0.11 kg ha-1 per application rate and soil-applying B at the currently recommended 0.56 kg ha-1 rate provided about the same net returns. Both methods were economically superior to not applying B. Applying agricultural limestone did not reduce B availability to the crop. Foliar-applying B with an adjuvant was economically superior to both soil and foliar applications without the adjuvant. These results can help farmers make B application decisions. For example, although using an adjuvant with foliarapplied B may appear costly to cotton producers, the adjuvant may increase lint yields more than enough to offset its cost.