A common characteristic of ultra-narrow-row cotton (Gossypium hirsutum L.) production is the use of high plant population densities (PPD) compared to wide-row cotton. Farmers are concerned about the high seed costs and technology fees associated with these high planting densities. The objective of this study was to evaluate the impact of changes in PPD on net revenues for ultra-narrow-row cotton (UNRC) production. Yield data for 1997 through 2000 were obtained from a UNRC PPD study at Milan, TN. Partial budgeting and marginal analysis techniques were used to identify the PPD that would maximize profit, using North Delta spot cotton quotations. Results indicated that small yield gains were achieved by increasing PPD in UNRC. In addition, price discounts for fiber quality became larger with higher PPD. Given the impacts of PPD on lint yields and price discounts for fiber quality, farmers may be able to increase the profitability of UNRC by using a seeding rate that is considerably smaller than required to maximize lint yields. Results suggest that favorable trade-offs exist between reduced yields from using a lower PPD and savings from reduced seed costs and technology fees combined with smaller price discounts. Farmers may encounter problems with weed control and harvesting at PPDs below 15.5 plants m-2, but should consider using PPDs as low as 15.5 plants m-2 to reduce seeding costs and curtail price discounts for fiber quality.