Aromatherapy is a Practical or Complementary Health Therapy that uses volatile concentrates extracted from plants called essential oils, in order to improve physical, mental and emotional well-being. Aromatherapy has been practiced historically and worldwide by nurses and, as in Brazil is supported by the Federal Nursing Council, it is relevant to discuss this practice in the context of Nursing through Theories of Nursing. This study of theoretical reflection, exploratory and descriptive, aims to discuss the pharmacognosy of essential oils, the historical trajectory of Aromatherapy in Nursing and the conceptions to support Aromatherapy in light of eight Nursing Theorists (Florence Nightingale, Myra Levine, Hildegard Peplau, Martha Rogers, Callista Roy, Wanda Horta, Jean Watson and Katharine Kolcaba), contributing to its inclusion as a nursing care practice.