Purpose: To provide farmers with access to salient knowledge on sustainability that could contribute positively to farmers' livelihoods, there is a need for knowledge facilitators. This paper examines the role of public extension workers as boundary workers in Indonesia on sustainable agriculture and challenges around them. Design/methodology/approach: To identify sustainability perspectives, this research uses Q-methodology which analyzes individual perspectives on sustainability, their differences, and similarities. This research also employs focus group discussions and interviews. In three regions in Indonesia. Findings: Q-method resulted in two perspectives. The technologists perceive sustainable agriculture as food security and the use of organic pesticides. They also believe that the responsibility for sustainable agriculture lies with extension workers and governments. The environmentalists believe the concept of sustainability implies the active prevention of environmental degradation. They also believe that everybody should take responsibility for sustainability. The paper determines that boundary work needs highly motivated extension workers; the ability to gain trust from farmers; and government support. Theoretical implication: This paper contributes to the literature on boundary work by connecting the concept of boundary work to agricultural extension. Practical implication: The results may be used as inputs for Indonesian policymakers to develop a guideline on sustainable agriculture for extension workers. Originality/value: In current studies on extension workers in developing countries, an analytical framework which employs the concept of boundary work is hardly found. Boundary work is a relevant concept to depict challenges extension workers are confronted with when brokering. Q-methodology aims to obtain individual perspective on a particular issue. This research provides insight on individual perspectives of extension workers on sustainable agriculture.