Our environment hosts a vast diversity of venomous and poisonous animals and plants. Clinical toxinology is devoted to understanding, preventing and treating their effects in humans and domestic animals. In Sri Lanka, yellow oleander (Thevetia peruviana, Sinhala 'kaneru'), a widespread and accessible ornamental shrub, is a popular means of self-harm. Its toxic glycosides resemble those of foxglove, against which therapeutic antibodies have been raised. A randomised placebo-controlled trial proved that this treatment effectively reversed kaneru cardiotoxicity. There are strong scientific grounds for the use of activated charcoal, but encouraging results with multiple-dose activated charcoal were not confirmed by a recent more powerful study. Venom of Russell's viper (Daboia siamensis) in Burma (Myanmar) produces lethal effects in human victims. The case of a 17-year-old rice farmer is described with pathophysiological interpretations. During the first 9 days of hospital admission he suffered episodes of shock, coagulopathy, bleeding, acute renal failure, local tissue necrosis, generally increased capillary permeability and acute symptomatic hypoglycaemia with evidence of acute pituitary/adrenal insufficiency. Antivenom rapidly restored haemostatic function but failed to correct other effects of venom toxins incurred during the 3h before he could be treated.