The massive increase of pesticide use in transgenic agriculture has sparked conflicts in the heartland of Argentinean agriculture. These political conflicts have led to an extension of pesticide regulation from the national and provincial to the municipal scale, and – simultaneously – to an extension from agrarian policy to environmental and health policy, and later to urban and regional planning. These intertwined territorial and sectoral changes to pesticide regulation cannot be explained by the existing literature about advocacy strategies which separates territorial and sectoral analyses. Based on the concepts of boundary control, politics of scale, and venue shopping, I elaborate three advocacy strategies: closing, opening, and change of territorial and sectoral decision arenas. I conducted a single case study of the conflict about pesticide use near the urban area of San Francisco (province of Córdoba) based on qualitative data collected during research trips to Argentina. The success and failure of the advocacy strategies applied by the pro-pesticide and the anti-pesticide coalitions explain the adoption of a strict municipal pesticide law in the town San Francisco dominated by agriculture, the subsequent failure of the implementation of a (unanimously adopted) law, and the later reform attempt to water down the municipal pesticide law. The empirical case shows that the advocacy strategies are not only selected based on the position of an advocacy group in the power relations, as stated in the literature, but that they are also based on the accordance of the beliefs and interests of an advocacy group to the valid policy definition.