Background: Cisplatin is a widely used platinum-based chemotherapeutic agent, but its gonadotoxic effects can damage ovarian tissue, oocytes, and developing follicles and may lead to primary ovarian insufficiency (POI). Adipose-derived stem cells (ADSCs) are being investigated as a potential regenerative treatment because of their paracrine, anti-apoptotic, and tissue-repair effects. Aim: To evaluate the effect of ADSC therapy on estrous cyclicity, body weight, and ovarian follicular morphology in a mouse model of cisplatin-induced POI. Materials and Methods: Thirty 6-week-old female BALB/c mice were included. Six mice received saline as controls, while 24 mice received cisplatin 2 mg/kg intraperitoneally once daily for 10 days to induce POI. After POI induction, cisplatin-exposed animals were continued as an untreated POI group (n=15) or an ADSC-treatment group (n=9). The ADSC group received 1×10⁶ cells suspended in 0.2 mL medium via the tail vein. Body weight and vaginal cytology were monitored daily, and estrous stages were classified as proestrus, estrus, metestrus, and diestrus. Ovaries were collected for histologic evaluation at the end of the study. Result: After cisplatin exposure, mean estrous cycle length increased from 3.97 days in controls to 6.4 days in the POI group (p<0.05). During the post-treatment evaluation, mean cycle length was 5.65 days in untreated POI mice (n=4) and 4.5 days in ADSC-treated mice (n=7), representing a statistically significant improvement after ADSC therapy (p=0.013). Cisplatin caused significant body-weight loss, reaching a mean of 18.0 g on day 6 after completion of cisplatin administration (p<0.01). Histologically, untreated POI ovaries showed follicular atrophy and prominent degenerative changes, whereas ADSC-treated ovaries showed more morphologically preserved primary, secondary, and antral follicles and relatively fewer degenerative changes. Exploratory manual counting in three representative whole-ovary sections per group showed total intact/growing follicle counts of 15.00±2.65 in controls, 6.00±2.00 in POI, and 8.67±2.89 in ADSC-treated ovaries. Conclusion ADSC treatment was associated with partial restoration of estrous cyclicity and ovarian follicular development in a cisplatin-induced POI mouse model. These findings support further investigation of ADSC-based regenerative therapy for chemotherapy-associated ovarian injury.