Legalization of medicinal and recreational cannabis use in numerous states within the USA has resulted in the increased commercial cultivation of cannabis. Outdoor cannabis farming operations present a variety of potential physical, chemical, and biological hazards that currently remain uncharacterized. Worker exposures to endotoxins were evaluated at an outdoor US cannabis farm during harvesting and processing activities. Endotoxin area air sample concentrations ranged from below the limit of detection to 15 endotoxin units per cubic meter (EU/m3). Endotoxin breathing zone measurements (2.8–37 EU/m3) were below the Dutch Expert Committee on Occupational Safety occupational exposure limit of 90 /m3. During confidential medical interviews, no adverse health effects were reported by workers while harvesting or processing cannabis. Further endotoxin exposure assessments should be performed especially in larger, indoor cannabis operations where a confined environment may result in higher endotoxin exposures than observed in this outdoor environment.