Invasive lobular carcinomas are the second most common type (5% to 15%) of invasive breast carcinomas. The most frequent sites of breast cancer metastasis are the local and distant lymph nodes, brain, lung, liver, and bones; metastasis to the gastrointestinal system, especially to the stomach, is rare. When a mass is detected in an unusual place in a patient with invasive lobular carcinoma, it should be kept in mind that such a mass may be either a second primary carcinoma or the metastasis of an invasive lobular carcinoma. In this report, we present a case of gastric metastasis from triple-negative invasive lobular breast cancer. It is important to make an accurate diagnosis by distinguishing gastric metastasis from breast cancer in order to select the best initial treatment for systemic diseases of breast cancer. Considering our case, healthcare professionals should take into account that cases with invasive lobular breast cancer may experience unusual metastases.