Objective. Self-poisoning with plant seeds or fruits is a common method of self-harm in South Asia. While most deaths follow ingestion of Thevetia peruviana (yellow oleander) seeds, other plants are locally common. During review of fatal injuries seen in a teaching hospital in eastern Sri Lanka, we noted cases of fatal self-poisoning with Cerbera manghas (sea mango, pink eyed cerbera, odollam tree) fruits. Methods. We reviewed the post-mortem records of the Batticaloa Teaching Hospital and extracted data on all cases of fatal injury. Results. During 2001 and 2002, 315 post mortems for injury were performed in Batticaloa Teaching Hospital. Intentional self-harm was responsible for 48.6% of cases. While T. peruviana was responsible for 33 deaths, C. manghas self-poisoning caused seven deaths. C. manghas cases had typical features of cardenolide poisoning with cardiac dysrhythmias and hyperkalemia. In the absence of pacing facilities and anti-digoxin Fab, management involved administration of atropine and of insulin and dextrose to lower serum potassium concentrations. Conclusions. C. manghas self-poisoning has only previously been reported from Kerala and Tamil Nadu in south India. While uncommon in other parts of Sri Lanka, it has become a common method of self-harm in one east coast district, accounting for 20% of fatal self-harm with plants in one hospital. Management was inadequate with the available resources, emphasising the need for an affordable antitoxin for plant cardenolide poisoning.