Rehabilitation nursing practice is concerned with many clinical manifestations that have an underlying biological impairment. Advances in managing these manifestations will depend in part on research that incorporates the biological dimension. The purpose of this article is to encourage more rehabilitation nurses to engage in biological research. To achieve this aim, several different categories of biological nursing research are described using rehabilitation nursing examples, biological measures and approaches are discussed, and possible general clinical outcomes, with examples from previously published biological nursing research, are described. Biological nursing research may enhance professional competence, improve patient care, and improve patient safety.