Clinical grape poisoning in two dogs (a 1.6-year-old male Shih Tzu and a 5-year-old female Yorkshire Terrier) was described in the present study. Clinical signs included decreased urine output in the Shih Tzu and ataxia in the Yorkshire Terrier after grape ingestion. The Shih Tzu died 5 days post-grape ingestion, while the Yorkshire Terrier died 3 days post-grape ingestion. Erythematous serosae and mucosae, multifocal red small intestinal foci, and blood and grape seeds were identified in the intestinal lumen. Brownish-yellow crystals were bilaterally identified in the renal pelvis. The primary histological findings were acute tubular necrosis of the proximal convoluted tubules, severe necrosis, and mineralization in the renal cortical tubules. Blood urea nitrogen, creatinine, and alanine aminotransferase were increased in the dogs. Many Korean veterinary clinicians have suspected clinical grape poisoning. However, to our knowledge, grape poisoning has not been identified by pathologic and clinicopathologic basis until this writing in Korea. Education and knowledge about the risks of grape poisoning is necessary for the prevention of accidental exposures.