Peutz-Jeghers syndrome (PJS) is characterized by an increased risk of gynecologic tumors. Gastric-type endocervical adenocarcinoma (GEA) is a rare non-human papillomavirus (HPV)-related tumor. We reported an uncommon case of a 39-year-old woman with PJS who developed GEA, superficial cervical vaginal myofibroblastoma, sex cord-stromal tumors with annular tubules of the ovaries, and cervical and vaginal high-grade squamous interepithelial neoplasia (HSIL). Before being verified GEA, the patient had been experiencing suspicious symptoms for over 9 years, with nabothian cysts and vaginitis being misdiagnosed. HSIL displayed widespread p16 immunostaining, and HPV DNA screening confirmed HPV-18 infection, although GEA was negative. Further, we verified