Pyocele in infants is rarely described in the literature, but it is an emergent condition that requires rapid recognition and treatment to prevent testicular loss. If peritonitis due to gastrointestinal perforation occurs, abdominal contamination may spread through a patent processus vaginalis in an infant, which may lead to pyocele. We report the cases of three infants with scrotal pyocele due to the spread of infection or inflammatory material from the intraperitoneal cavity through a patent processus vaginalis. Two infants were surgically treated, while the other was treated with percutaneous aspiration and intravenous antibiotic administration. Although rare, pyocele should be considered in the differential diagnosis of acute scrotum in infants, especially in infants who previously had peritonitis due to gastrointestinal perforation.