Inguinal nodal disease has been reported to be a rare metastatic site for cancer of Mullerian origin. However, isolated inguinal nodal disease has not been reported in literature. We report a case of inguinal lymph node endometrioid adenocarcinoma, with no gynaecological primary detected. Our patient is a 48-year-old lady with no significant past medical history. She presented with a left groin lump to the general surgery department and an excision biopsy revealed histology consistent with metastatic adenocarcinoma, in keeping with primary from the female gynaecologic tract (CK7, PAX8, estrogen receptor positive; GATA3, CDX2 negative). She reported occasional intermenstrual bleeding therefore hysteroscopy and endometrial curettage was performed, revealing normal vagina, cervix, and a benign endometrial polyp and focal endometrial hyperplasia with no atypia. Computed tomography of the thorax, abdomen and pelvis, and magnetic resonance imaging performed revealed no significant pathology besides a cluster of prominent left inguinal lymph nodes. Screening oesophageal gastroduodenoscopy and colonoscopy performed was unremarkable. After discussion at multidisciplinary team, a total hysterectomy, bilateral salpingo-oophorectomy and complete debulking of left inguinal lymph nodes was performed. Final histology of uterus and bilateral tubes and ovaries did not reveal any malignancy, except for endometrial hyperplasia without atypia, and focal endometriosis on left ovary. The inguinal lymph nodes removed were found to be consistent with endometrioid carcinoma. Our hypotheses for isolated endometrioid carcinoma in the inguinal lymph node includes malignant transformation of ectopic endometriotic deposit or endosalpingiosis in the inguinal lymph node.