Oleander is a large ornamental evergreen shrub that may grow 20–25 ft in height. During the summer months’ large clusters of white, pink, red, or yellow (yellow oleander) flowers appear at the ends of the branches. All parts of the plant contain cardiac glycosides. Oleander is a common source of serious plant poisoning. In South Asia, particularly Sri Lanka, also present in Libya desert and some house gardens with white and pink types, oleander has become a notorious method of suicide. Toxicity is largely characterized by gastrointestinal symptoms and cardiac abnormalities. Tachy or bradydysthythmias may be present in addition to slowed conduction and heart block. Hyperkalemia is common and correlates with severity of poisoning. A specific antidote—digoxin-specific fragment antigen-binding region (Fab region)- is available. In Mediterranean climates oleanders can be expected to bloom from April through October, with the heaviest bloom usually occurring between May and June. Free-flowering varieties like 'Petite Salmon' or 'Mont Blanc' require no period of rest and can flower continuously throughout the year if the weather remains warm. The exact nature of plant poisoning varies from region to region, but certain plants are almost ubiquitous in distribution and among these, Oleander is a garden plant that features in many homes. Incidents of poisoning from these plants are therefore not uncommon and may be the result of accidental exposure or deliberate, suicidal ingestion of the toxic parts. An attempt has been made to review the management principles with regard to toxicity of these plants and survey the literature in order to highlight current concepts in the treatment of poisoning resulting from both plants. Ingestion of its seeds results in a clinical picture similar to digoxin toxicity. It contains cardiac glycosides that are toxic to cardiac myocytes and autonomic system. Cardiac glycosides of oleander cause poisoning by inhibiting plasmalemmal Na+/K+-ATPase. Results: The poisoning effects of plant or their active alkaloids induced infiltration of cells with hemorrhage and sever negative changes in the lung, induce lesions, and infiltration of inflammatory cells into the portal spaces with scattered necrosis of hepatocytes in the liver, cardiac toxicity of the plant in the heart were included, induced varying degrees of hemorrhage, myocardial degeneration, and necrosis. It also induced arrhythmia, sinus bradycardia, and prolonged P-R interval in electrocardiographic records. Conclusions: The toxic effects of N. oleander are mostly related to its inhibitory effects on the Naþ-Kþ ATPase pump in the cellular membrane. However, the exact molecular mechanism involved in the toxicity of N. oleander is not clear.