This study analyzed food poisoning articles in the Joseonwangjosillok to acquire historical evidence. The study method used case studies from the textual content of the Joseonwangjosillok. In all, there were fifteen cases of food poisoning in spring (60%), four cases in summer (16%), five cases in fall (20%), and 1 case during winter (4%). Most cases of food poisoning occurred during spring, followed by fall, then summer, and the least during winter. Foods that caused poisoning were as follows: twelve cases of seafood (48%), three cases of vegetables (12%), two cases of meat (8%), and eight cases of poisonous food (32%). Maximum cases pertained to seafood poisoning, which also spiked during spring. This could be attributed to the increased number of planktons as the sea temperature rose during spring. Due to the increased plankton, shellfish absorbed more toxins. The consumption of increasingly toxic shellfish resulted in more cases of food poisoning. The food poisoning frequency was the most severe during the 18th century, followed sequentially by the 15th, 16th, and 17th centuries, and was the least severe during the 19th century. Joseonwangjosillok showed that food poisoning cases happened most during social events where many guests or family members gathered to eat.