Electronic Journal of Differential Equations, Vol. 2010(2010), No. 124, pp. 1-25. Title: Existence of square-mean almost periodic mild solutions to some nonautonomous stochastic second-order differential equations Authors: Paul H. Bezandry (Howard Univ. Washington, DC, USA) Toka Diagana (Howard Univ. Washington, DC, USA) Abstract: In this paper we use the well-known Schauder fixed point principle to obtain the existence of square-mean almost periodic solutions to some classes of nonautonomous second order stochastic differential equations on a Hilbert space. Submitted May 4, 2010. Published August 30, 2010. Math Subject Classifications: 34K14, 60H10, 35B15, 34F05. Key Words: Stochastic differential equation; Wiener process