As nitrogen fertilizer prices increase, there is more interest in comparing different nitrogen fertilizer sources for cotton all across the belt. First, a review of how different inorganic nitrogen fertilizers are manufactured will be presented. A discussion of organic nitrogen sources will also be included. A comparison of the characteristics of the nitrogen fertilizers will then be presented. Finally, a review of nitrogen sources commonly used in different regions of the US Cotton belt will be presented. A look to the future including trends in nitrogen fertilizer sources and price will conclude the presentation.