G. Gallavotti Chaotic Hypothesis and Universal Large Deviations Properties (98K, TeX (as plain as it can be)) ABSTRACT. Chaotic systems arise naturally in Statistical Mechanics and in Fluid Dynamics. A paradigm for their modelization are smooth hyperbolic systems. Are there consequences that can be drawn simply by assuming that a system is hyperbolic? here we present a few model independent general consequences which may have some relevance for the Physics of chaotic systems.