Invasive alien plants (IAPs) are a significant cause of socio-ecological change in Sri Lanka. Many studies have focused on the ecological dimensions of this problem, but few have addressed sociological factors such as the knowledge and perceptions of individuals and groups tasked with addressing IAPs. This study investigates how IAP issues are understood and perceived by professional forest and wildlife officers in Sri Lanka. The data analyzed were gathered using a questionnaire that covered three themes: the respondents' ability to identify IAPs, the impacts of IAPs and the threats they pose, and knowledge regarding control and mitigation. The questionnaire was completed by 186 field officers, and the resulting descriptive statistics and a probit regression analysis were used to analyze the data. The results show that almost all of the participating forest and wildlife officers were aware of the problems associated with IAPs but more than 75% of them lacked an accurate understanding of scientific means for controlling them and control policies established by the government of Sri Lanka. Generally, wildlife officers had a better understanding than forest officers. In addition, the analysis shows that officers' knowledge and perceptions of IAPs were positively correlated with their level of education and position within the organization. The analysis points to several recommendations for Sri Lankan officials when designing and implementing comprehensive policies and professional programs, particularly for lower-level field officers.