A 4-yr old patient was admitted to the hospital with pain attacks in his extremities, tachycardia, hypertension, increased sweating, behavioral changes and weight loss. Extensive examinations eventually revealed an acute mercury poisoning. The mercury levels in blood and urine were 36.7 µg/l and 90 µg/g creatinine, respectively. A facial cream bought online, containing approximately 18 % mercury, was identified as the primary source of intoxication. The symptoms improved after disposal of the cream and chelation therapy. Biomonitoring of the mother and the brother, who remained asymptomatic, indicated an increased exposure to mercury, too. The mother, who had been using the cream for approximately three months, denied its application on her children. Further analyses, home visits and interviews suggested that the child was accidently intoxicated by skin-to-skin contact with the mother. Other mercury sources were excluded and mercury levels decreased considerably over time. The family will be closely monitored to exclude any long-term health issues. Lessons learnt from this case of an acute mercury intoxication is that even skin to skin contact with a mercury containing cream can have significant negative health effects for a child.