In cotton cultivation, insecticide a.i. against red spider mite (Tetranychus cinnabarinus (Biosduval)) has approximately applied as 3,211.6 kg. For this kind of an insect control, in 2013, five active ingredients were used in cotton cultivation in Adana, Turkey. These active ingredients included abamectin, etoxazole, hexythiazox, propargite and spiromesifen. The objective of this research was to determine a buffer zone for the recommended dose by manufacturer (RD) and applied dose by farmers (FD) according to aquatic organisms in cotton cultivation. In this research, all a.i., risk index (RI) values were assessed according to distance (Z) between nozzle and downwind field for Dutch Drift Model (DDM), and field border and downwind field for German Drift Model (GDM). Buffer zones (Z(RI=1)) for all a.i. were calculated by developed equations via RI values at different distances. Buffer zone was found as >= 18 m for abamectin and >= 16 m for propargite in RD. It was determined as >= 27 m for abamectin and >= 25 m for propargite in FD. Buffer zone was assessed as >= 3 m for etoxazole and >= 4 m for spiromesifen in RD. It was calculated as >= 4 m for etoxazole and >= 5 m for spiromesifen in FD. In this study, buffer zones for FD were determined to be wider than RD's in two models.