The purpose of this paper is to construct a class of orthogonal integrators for stochastic differential equations (SDEs). The family of SDEs with orthogonal solutions is univocally characterized. For this, a class of orthogonal integrators is introduced by imposing constraints to Runge-Kutta (RK) matrices and weights of the standard stochastic RK schemes. The performance of the method is illustrated by means of numerical simulations. (c) 2005 Elsevier B.V. All rights reserved.