Introduction: Obesity is a major risk factor in the development of endometrial cancer (EC) in young patients of reproductive age. Fertility sparing treatment is a viable option for a select group of patients with early EC, and involves systemic and intra-uterine hormonal therapy. Weight loss has been associated with improved outcomes in this group. Bariatric surgery (BS) has been shown to be the most efficient and durable method of weight loss in obese patients. However, there is a paucity of data studying the benefit of BS as part of fertility sparing treatment. Methods: We present a retrospective case series of five patients who are undergoing fertility sparing treatment for early EC, who also underwent BS for treatment of obesity and related comorbidities. We aim to show early regression of EC for all the patients and also report on the other health benefits of BS. Results: All five patients in the series achieved regression of EC within six months of undergoing BS. They also achieved significant weight loss consistent with previous studies, and three patients who had comorbidities related to obesity had remission of these conditions. One of the patients with EC regression also managed to conceive with IVF. Conclusion: Patients on fertility sparing treatment for early EC who underwent BS was associated with early regression within 6 months, significant weight loss and resolution of comorbidities. BS could be a promising component of fertility sparing treatment. Long term, prospective studies are required to confirm the benefits reported in this case series.