The objective of this work was to study the dermal exposure of workers to residues of the deltamethrin, applied in cotton. After 3 minutes of application four people dressed a group with cotton clothes (pant, shirt and gloves), entered and stayed in the treated area by 30 minutes, simulating an insect sampling. The procedure was repeated after 60 and 300 minutes and 1, 3, and 7 days of the application. The clothes were cut and put in plastic bags, and stored cold at -18 ºC  until analyses was performed. The analytical method consisted on the extraction of deltamethrin residues with a ethyl acetate and the quantitative determination was done by gas chromatograph. Exposure was extrapolated to a work day of 8 hours. To evaluate safety's conditions at work was estimated the Working Condition Unsafe (margin of safety – MOS <1), Poisonous Dose (%PD/day), Dermal Dose Tolerable and the estimate of Safe Work Duration (SWD). The corresponding group for the forearms/arms/hands concentrated 61.27% of present residues in the clothes. The residues found on the clothes, chest, legs, lame and back, were 13.40, 9.33, 9.32, and 6.65%, respectively.  Results of deltamethrins amounts trapped on cotton clothes showed that 24h as a reentry interval for Decis 25 EC is overestimated.