In Bangladesh, influenza A(H5N1) viruses are endemic in poultry. Processing infected chickens can aerosolize viruses, increasing the risk for human infections. We evaluated particulate matter (PM2.5) mass concentration during slaughtering and defeathering methods used in live bird markets in Bangladesh to identify solutions to reduce aerosol exposure. We slaughtered 675 chickens using cones and barrels with 3 lid types and defeathered 45 chickens using a defeathering machine with 5 lid types. We interviewed 3 slaughterers to understand method preference. For slaughtering, barrels with a solid or star-cut lid reduced PM2.5 mass concentrations by 65%–73% compared with uncovered barrels. For defeathering, machines fully covered by a solid lid or lid with a hole and pivot door reduced PM2.5 mass concentrations by 50% compared with machines with no lid. Slaughterers preferred barrels covered with solid lids and defeathering machines covered with solid or hinged lids. Those methods might reduce aerosol exposure during poultry processing.