A well-differentiated ovarian neuroendocrine tumour (NET) associated with a mature cystic teratoma is rarely reported in the literature: the histologic diagnosis of these tumours is challenging due to the absence of defined guidelines for such lesions. Molecular imaging using [ 68 Ga]Ga-DOTATATE PET/CT can play a pivotal role in evaluating somatostatin receptor (SSTR) expression for NET and assessing morphologic features for diagnosing teratoma, especially in patients of ovarian NET associated with mature cystic teratoma in single individual. In addition, [ 68 Ga]Ga-DOTATATE PET/CT offers advantages for implementing theranostic approaches in the treatment of these rare tumours, should this be contemplated.