This paper considers the issue of nursing science. Nursing, as an art, has long been accepted as integral to nursing. Nursing, as a science, however, is a more recent concept. Nursing science is viewed as a threat to the profession by its opponents, while the proponents of nursing science see it as a promise for advancement of the discipline. This paper examines the issue of nursing science by looking at its history and development, the definition of science, and five factors critical to the nursing science issue. The author concludes that nursing science is, in varying respects, both a threat and a promise. It is clear that the preponderance of evidence favours the promise nursing science holds for the profession of nursing. It is not a matter of choosing either art or science, but rather skillfully blending both for the betterment of nursing. Both art and science are necessary in nursing—neither, however, is sufficient.