Although gastrointestinal involvement by metastatic malignant melanoma is common but primary gastrointestinal (GI) melanoma has been reported in rare cases. In this study we report two cases of primary gastrointestinal malignant melanoma that one of them is a known case of neurofibromatosis type 1 (NF1). Both cases showed no evidence of any lesions in skin and eye. Malignant melanoma of GI tract in patient with neurofibroma is reported with hypothesis of a possible relation between two pathologies. Both primary GI melanoma and combination of NF1 with primary GI melanoma are rare entities discussed in this article.