Yellow oleander (
Thevetia peruviana
), known for its cardiac glycosides, can cause severe poisoning with varied clinical manifestations, primarily affecting the cardiovascular system. We present a unique case of a 57-year-old Saudi woman with a history of type 2 diabetes, dyslipidemia, and previous meningioma excision who ingested 3.4 grams of yellow oleander fruit, mistaking it for an edible fruit. Remarkably, she remained asymptomatic with no gastrointestinal, neurological, or cardiovascular symptoms. Examination and investigations, including electrocardiograms and laboratory tests, showed no abnormalities. Despite the known high toxicity of yellow oleander and its documented fatal cases, our patient's asymptomatic presentation is rare. This case highlights the importance of close monitoring and observation in yellow oleander ingestion cases, even in the absence of symptoms, due to variable absorption kinetics and potential delayed onset of toxicity. Our findings also underscore the need for public health awareness regarding the identification and dangers of toxic plants like yellow oleander, especially as they are commonly grown at home.