Electronic Journal of Differential Equations, Vol. 2001(2001), No. 64, pp. 1-8. Title: Stability properties of positive solutions to partial differential equations with delay Authors: Gyula Farkas (Istvan Szechenyi College, Hungary) Peter L. Simon (Univ. of Leeds, Leeds, UK) Abstract: We investigate the stability of positive stationary solutions of semilinear initial-boundary value problems with delay and convex or concave nonlinearity. If the nonlinearity is monotone, then in the convex case $f(0)\le 0$ implies instability and in the concave case $f(0)\ge 0$ implies stability. Special cases are shown where the monotonicity assumption can be weakened or omitted. Submitted June 21, 2001. Published October 8, 2001. Math Subject Classifications: 35R10, 35B99. Key Words: semilinear equations with delay; stability of stationary solutions; convex nonlinearity; concave nonlineariry.