Dermatitis (skin inflammation) caused by the oil of poisonous plants is an occupational hazard for U.S. military members who are assigned and train in endemic areas. Plant dermatitis can cause significant disability, substantial medical costs, and lost duty time. During the 11-year surveillance period there were 73,725 cases of plant dermatitis diagnosed in active component service members (rate: 5.3 per 1,000 person-years [p-yrs]). The overall incidence rates remained relatively stable between 2010 and 2015, increased in 2016 and 2017, then decreased in 2018 through 2020. Compared to their respective counterparts, incidence rates were highest among male service members (5.7 per 1,000 p-yrs), the youngest (<20 years) service members (8.4 per 1,000 p-yrs), non-Hispanic White service members (7.5 per 1,000 p-yrs), members of the Army (7.7 per 1,000 p-yrs) and Marine Corps (6.5 per 1,000 p-yrs), and among those in combat-related occupations (11.9 per 1,000 p-yrs). More than half of the cases occurred during summer months and about one-third of all cases were diagnosed at 4 installations: Fort Benning, Georgia (n=11,257); Camp Pendleton, CA (n=5,399); Fort Bragg, NC (n=4,259), and Fort Campbell, KY (n=3,221). Service members, particularly young individuals in combat-training in endemic states, should be informed of the risks associated with exposures to toxic plants and advised on personal protective measures.