Yellow oleander (Thevetia peruviana) is an evergreen shrub belonging to the family Apocynaceae. It is cultivated in warm regions as an ornamental plant because of its beautiful yellow flowers and attractive appearance. The plant has branched stems and long, narrow, relatively thick leaves. The leaves are characterized by their glossy green color, which helps the plant maintain its appearance throughout most of the year. The flowers are produced in small clusters and are characterized by their funnel-shaped form and yellow or yellow-orange color. After flowering, distinctive fruits develop that contain large seeds. All parts of the plant, particularly the seeds, contain potent cardiac glycosides, such as thevetin, making the plant poisonous if ingested. These compounds represent part of the plant’s chemical defense, reducing its exposure to herbivory. The plant is capable of growing in warm regions and tolerating certain periods of drought, which makes it suitable for use in gardens and along streets. Its flowers provide food resources for some insects and contribute to increasing plant diversity in cultivated environments. The study of yellow oleander is important for understanding the relationship between plant defensive chemical compounds and its ecological and ornamental characteristics. It also demonstrates that some plants with high aesthetic value may simultaneously contain highly toxic compounds, and therefore should be handled with caution.