We report a case of box-jellyfish related envenomation in a 40 year old tourist that occurred in Sihanoukville, Cambodia, in the Gulf of Thailand. Symptoms that appeared within a few minutes associated intense pain, hand edema and large edematous and erythematous flagellations in the stung skin areas. Antibiotics and corticosteroids were delivered. Inflammatory signs and skin lesions disappeared within 15 days followed by crusts then scars. Jellyfish at risk for humans are generally found in tropical seas and their geographic distribution seems to spread. As it is difficult to prevent this kind of accident, travelers should be aware of the first acts to perform, such as appropriate cleaning of the wound, the interest of vinegar usage, the administration of analgesics and corticosteroids in case of significant inflammatory signs.