The crystal structure and physical properties of the Sr2FeMO6 (M = Mo, W) double perovskite have been investigated. Analysis of the X-ray powder diffraction pattern based on Rietveld refinement indicates that Sr2FeMoO6 and Sr2FeWO6 have tetragonal cell (space group: I4/m) and orthorhombic cell (space group: Immm), respectively. The Curie-Weiss fit for Sr2FeWO6 gives Curie constant, C = 6.08 and Weiss temperature, theta = -32.6 K. The small and negative value of theta suggests the existence of both weak ferromagnetic and antiferromagnetic interactions at low temperature. The antiferromagnetic interaction dominates over the weak ferromagnetic one. (c) 2005 Elsevier B.V. All rights reserved.