Electronic Journal of Differential Equations, Vol. 2010(2010), No. 75, pp. 1-15. Title: Reaction-diffusion system of equations in non-stationary medium and arbitrary non-smooth domains Author: Sikiru Adigun Sanni (Univ. of Uyo, Nigeria) Abstract: A system of non-linear partial differential equations describing one-step irreversible reaction, reactant to product, in a non-stationary medium and non-smooth domain is considered. After obtaining the necessary a priori estimates, the existence of a unique local strong solution to the system is proved using a fixed point theorem. Submitted November 27, 2009. Published May 21, 2010. Math Subject Classifications: 35B40, 35K57, 80A25. Key Words: Irreversible reaction; reactant diffusivity; thermal conductivity; a priori estimates; Banach's fixed point theorem.