Bone histology, the study of bone tissue, has become a critical tool in the field of paleobiology as a proxy for life-history information, such as growth rates, that is otherwise inaccessible from fossils. However, the bulk of bone histological research has focused on birds, crocodilians, and large-bodied mammals, leaving the extent to which bone microstructure acts as an indicator of growth rates among small mammals largely unknown. Therefore, we generated thin sections from the limb bones (e.g., tibiae, humeri, and femora) of a taxonomically diverse sample of 12 extant, small-bodied (<1 kg) mammals in an attempt to build a framework upon which we may make inferences about the evolution of mammalian growth dynamics. In general, vascularity is low or absent in our samples, and the degree of vascularity appears to decrease with decreasing body mass. All specimens exhibit two types of bone matrix: well-organized parallel-fibered bone and disorganized woven bone. Often, this parallel-fibered tissue lines the interior and exterior of the bone cortex, bordering an intermediate band of woven tissue. This middle band likely represents a period of rapid bone deposition, possibly corresponding with rapid growth in early ontogeny, while the parallel-fibered bone represents deposition after growth had slowed. We hypothesize that the structurally competent parallel-fibered bone bordering the cortex may act to buffer the intermediate, structurally weak, woven bone against mechanical strain during locomotion. To test these hypotheses, we will compile existing life-history data and quantify the histological features of our sample using NIS Elements photo documentation software, and apply multiple linear regression models to test for relationships of significance. By investigating the impact of life-history characteristics upon small mammal bone microstructure, we hope to make important inferences about the lives of extinct small mammals, and thus create a more comprehensive understanding of mammalian growth dynamics.