In the early 1970s the need for a precise and computerizable language of nursing phenomena was identified. This need stimulated the formation of the National Conference Group for the Classification of Nursing Diagnoses. The group began the work of identifying nursing diagnoses and developing a taxonomic structure for their classification. Based on the initial success with the development of nursing diagnoses, the conference group became the North American Nursing Diagnosis Association (NANDA). There are two benefits of taxonomic development within nursing: one is scientific in nature, while the other is applied or practical. The development of this taxonomy has occurred over a span of 17 years including nine national conferences. Details of this development have been abstracted from the proceedings of the nine conferences and the minutes of the Taxonomy Committee in order to explicate the taxonomic structure. The rules for the classification, developed by the committee, are presented. Future directions for taxonomic development and collaboration with other health care professions are proposed.