This paper calls attention to the factors that contribute to predicting behavioral intention to cultivate medicinal and aromatic plants (MAPs) in farmlands, as social-psychological and microeconomic features of the adopter and nonadopter farmers are compared. Against the previous studies that have established inductive-based hypotheses, this research, in turn, benefitted from a deductive-based approach (i.e., theory-driven) and recognized a knowledge gap of attitude-intention behavior and cost-benefit behavior in the case of the adoption of the cultivation of MAPs. Given the nature of the respective hypotheses, the study used a sample of 312 farmers, randomly clustered and selected from the rural areas of Sari and Maragheh Townships, Iran. The former is a leading site respecting the cultivation of MAPs (n1 = 89), and the latter is a less or underdeveloped region (n2 = 223). Respondents were asked to complete a self-implemented questionnaire, conceptually designed by the theory of planned behavior and rational choice theory and confirmed by Cronbach's alpha reliability method. Using the linear regression model, it was revealed that attitude, subjective norms, perceived behavioral control (PBC), and perceived costs are the drivers of intention. In contrast with the nonadopter farmers, adopter farmers have a more positive attitude (Hedges' g = 0.39), subjective norms (Hedges' g = 1.04), PBC (Hedges' g = 1.15), and intentions (Hedges' g = 0.93), as well as lower perceived costs (Hedges' g = 0.56). The study concluded that findings give insight to agricultural policymakers and extension agents in the field of promoting the cultivation of MAPs as a complement to conventional cropping patterns.