We present the case of a 35-year-old male with first degree family history of gastric cancer (father diagnosed at the age of 45), that was presumed to have gastric cancer himself when evaluating the features of his upper endoscopy performed after hematemesis. Surprisingly, no cancer cells were found in the biopsies. Thanks to a different diagnostic suspicion subsequent to performing a full clinical history, a more favorable diagnosis was reached: gastric syphilis.