This work describes the use of magnetic resonance (MR) microscopy to examine changes in tibial trabecular bone structure in mice following 28 days of hindlimb suspension, a model simulating the effects of microgravity in rodents. In this first MR study involving mice, analysis of 3D images showed that apparent bone volume fraction, trabecular number, and trabecular thickness were decreased, and apparent trabecular spacing increased, significantly (P < 0.05) in hindlimb-suspended mice compared to controls. These changes agreed well with light microscopy measurements from an independent study and also with actual spaceflight experiments with rats.