The most common cause of hyperprolactinemia is prolactinoma. In addition, it is necessary to exclude potential physiological and pharmacological factors as well as health disorders to determine the cause of hyperprolactinemia. However, few studies have linked elevated prolactin (PRL) levels to ovarian cancer (OC). OC cells can ectopically release PRL, which then attaches to PRL receptors (PRLRs) in ovarian tissue and initiates signaling cascades that induce OC carcinogenesis. Therefore, we can consider PRL as a biomarker or tumorigenesis factor for OC. Furthermore, both PRL and PRLRs are potential therapeutic targets. A 50-year-old female presented with complaints of breast enlargement, soreness, and hyperprolactinemia, in addition to advanced OC. Hyperprolactinemia along with advanced high-grade serous ovarian carcinoma. Due to the patient's fear of confined spaces, magnetic resonance imaging of the pituitary gland under general anesthesia was prescribed to rule out pituitary pathology. Magnetic resonance imaging was not performed due to the deterioration of the underlying condition, and the patient died 2.5 years after the diagnosis of OC. Hyperprolactinemia caused by OC is a rare condition for which there is a lack of literature and case studies. PRL produced by OC tissue binds to PRLRs in an autocrine or paracrine manner, initiating signaling cascades that induce OC tumorigenesis. In combination with other biomarkers, PRL may serve as a biomarker for OC. To establish the relation between OC and elevated PRL levels, additional large-scale population studies are required, with diagnostic and treatment procedures coming first.