Objective: Peripheral precocious puberty (PPP) is the precocious development of secondary sexual characteristics without pulsatile gonadotropin-releasing hormone (GnRH) secretion. In girls, PPP suggests a hyper-oestrogenic state, such as autonomous ovarian cysts and McCune–Albright syndrome (MAS). We aimed to investigate PPP in girls with ovarian cysts, with or without MAS. Design: A retrospective study design was used. Patients and Measurements: The study included 12 girls diagnosed with ovarian cysts with PPP between January 2003 and May 2022. Pelvic sonography was performed in cases of vaginal bleeding or areolar pigmentation in PPP. The clinical characteristics, clinical course and pelvic sonographic findings of girls with ovarian cysts were investigated. Results: We found 18 episodes of ovarian cysts in the 12 girls. The median size of the ovarian cysts was 27.5 mm. Five of the girls were diagnosed with MAS. The median time to spontaneous regression was 6 months. Later, 4 out of 12 girls progressed to central precocious puberty (CPP), and three of them had a recurrence of ovarian cysts. Compared to the non-recurrent and recurrent groups, there was a difference in peak luteinizing hormone (LH) in the GnRH stimulation test and period to cyst regression. Conclusions: Most ovarian cysts in PPP spontaneously disappear. However, this could be one of the findings of MAS. Some girls progress from PPP to CPP. Therefore, follow-up is necessary for ovarian cysts in patients with PPP. The recurrence of ovarian cysts may occur when spontaneous regression is prolonged.