Litter-dwelling arthropods comprise about three-fourths of the total animal biomass in tropical forests. These invertebrates are involved in many interspecific interactions, from mutualism to predation. We report herein the predation of a scorpion by an immature assassin bug (Harpactorini) during a nocturnal manual search for scorpions in a fragment of the Brazilian Atlantic Forest. The specimens were found 15 cm above the ground on a seedling, and the prey was two-fold larger than the predator. The assassin bug had its rostrum inserted into the pleura of a juvenile Tityus pusillus Pocock, 1893 scorpion, between the first and second segments of the mesosoma; when disturbed, the predator jumped to the leaf litter without releasing its prey. To the best of our knowledge, this is the first report of juvenile predator-prey interactions between a heteropteran and a scorpion in this biome.