Cotton yield loss by weed genera (Table 1), acreage infested by weed genera (Table 2), herbicide use information (Table 3), and bales reduced for grass contamination (Table 4) are summarized for cotton producing states. It must be emphasized that all information, except for the grassy bale data, provided in this report are estimates made by scientists and coworkers in the respective states. None of the data in Tables 1 through 3 has been authenticated. Two reports are included from Alabama and Louisiana which document weed infestation levels occurring in cotton fields at harvest. Inferences concerning yield loss may be made by using the data provided in these reports in conjunction with published information describing the yield losses attributed to specific weed species.