The emergence of infectious diseases is often associated with changes to host-pathogen ecology, and wildfires are known to profoundly modify the ecology of terrestrial and freshwater ecosystems. Nevertheless, few studies have employed manipulative experiments to quantify effects of fire on infections across parasite species. In a mark-recapture study, prescribed burns did not affect densities of Cuban treefrog (CTF; Osteopilus septentrionalis) definitive hosts. However, a prescribed burn field experiment and before-after-control-impact mesocosm study revealed that fire decreased a skin-penetrating nematode in CTFs by killing the parasite’s soil- dwelling, free-living stage. Additionally, prescribed burns were associated with increases in a terrestrial acuariid nematode and several aquatic trematode metacercariae in CTFs, likely by increasing intermediate host densities. We found no evidence of recovery in the trajectories of these parasites seven years after burns. These results suggest that fire can have predictable and long-term direct and indirect positive and negative effects on parasite transmission.