Metastatic adnexal adenocarcinoma not otherwise specified (AANOS) is a rare and aggressive tumor with little evidence about treatment options. We describe a case of metastatic AANOS that showed a positive response to carboplatin and paclitaxel. This response is novel in the current medical literature. We report the case of a 72-year-old male with no significant past medical history, presenting with a 4 cm occipito-temporal skin mass. A cutaneous biopsy and staging confirmed the diagnosis of primary cutaneous AANOS, with no evidence of metastasis. The patient underwent radical surgical excision followed by adjuvant radiotherapy. After 44 months of follow-up, the disease recurred locally and progressed with pulmonary, mediastinal, and bone metastases. The patient was started on a systemic chemotherapy regimen of carboplatin and paclitaxel. A near-complete response was observed after three months, which was sustained after one year of follow-up. Given the rarity of these tumors, no treatment guidelines are available, and evidence is based on single case reports and a few case series. A combination of carboplatin and paclitaxel provides a strong inhibition of cell mitosis and allows for the administration of lower doses at a higher frequency, thus balancing efficacy with reduced toxicity. Combination carboplatin and paclitaxel can be an effective treatment for metastatic AANOS.