Climate change is increasing the severity of pest and pathogen infestations affecting forests. Resulting shifts in disturbance patterns can have substantial ecological, social, and economic impacts on forested ecosystems and their dependent communities. Researchers are actively investigating methods to improve tree resistance to specific pests and pathogens and enhance forest resilience. This could include using biotechnologies to genetically engineer tree species with particular resistance mechanisms, such as the American chestnut. Genetic engineering has been widely controversial in the agricultural industry due to concerns about potential human health and environmental impacts. However, less is known about how people perceive the use of biotechnologies in forested settings. Previous research shows that an individual’s environmental beliefs influence their risk perceptions and attitudes about forest management. This study addresses two overarching research questions: (1) how do the risks and benefits conservation professionals and volunteers perceive about forest biotechnology influence their attitudes toward using it?; and (2) how do conservation professionals and volunteers invoke their environmental ethics and beliefs to describe and justify their attitudes toward forest biotechnology? To answer these questions, we conducted 33 semi-structured interviews with conservation and land management professionals within the U.S. Pacific Northwest during summer 2019. Results suggest that participants are most commonly concerned about potential unintended ecological consequences that might arise from forest biotechnology and rely on their knowledge and beliefs about agricultural biotechnology to inform their beliefs and attitudes toward forest biotechnology. Further, participants’ environmental beliefs and ethics influenced their attitudes toward using forest biotechnology. Commonly, interviewees justified their attitudes toward using forest biotechnology using arguments based in their ethical position about whether humans should be involved in protecting or managing natural environments. This research contributes to our understandings of the contexts and conditions that influence attitudes toward forest biotechnology – considerations that are critically important as the scientific community investigates ways to address the pest and pathogen outbreaks that climate change is exacerbating.