13pgs, This study aims to analyze the influence of neighborhood effects (NE) on tea farmers' intention to convert from traditional to organic farming in the mountainous areas of northern Vietnam. It differs from previous studies in two aspects. First, we combine the theory of planned behavior and the theory of herd behavior to explain farmers' intention to convert from traditional to organic farming, focusing on the impact of the NE. Secondly, to measure NE, we use a combination of questionnaires and methods of measuring herd behavior by McCartney and Shah. Using the generalized structural equation modeling and data collected from 263 tea farmers in Thai Nguyen, we found that NE has a positive and direct significant effect on farmers' intention to convert to organic tea production in the case where neighbors both live nearby and have a close relationship with the subject. In addition, it indirectly impacts farmers' conversion intention through attitude, subjective norms and perceived behavior control. To encourage tea farmers to convert to organic farming, policymakers and extension workers should take advantage of the NE to increase farmers' confidence about the benefits and the possibility of successful organic farming.
