ABSTRACT This paper argues for a syntropic, multilevel conceptualization of ecotoxicology beyond the simple organism-level effects of poisons. Such a concept embraces complex systems, ecotoxicology, ecoepidemiology, and ecosystem health and integrity. One way of thinking about the relative stability of ecosystems and their biological and nonbiological components is the conditional (Bayesian) probability of their coherent versus incoherent response to perturbation. Anthropogenic and natural stress may change the structure, function and/or organization of dissipative systems at any level, compromising self-regulation and making unstable incoherent responses more probable. Syntropic ecotoxicology argues for increased understanding of how ecotoxic agents or events may be disrupting self-regulating mechanisms at the molecular, cellular, organismal, population, and/or community levels—their multilevel ecotoxicodynamics. In parallel, and adaptive to new knowledge, interdisciplinary teams of scientists, policy makers, and other stakeholders must collaborate effectively to mobilize and integrate financial, human, material, and information resources to prevent and control existing priority deterministic stressors.