The invention relates to the use of substance P antagonists and, in particular, the use of non-peptidic NK1 receptor antagonists for the treatment of cancer and, more specifically, human melanoma, neuroblastoma, glioma, human Hodgkin's lymphoma KM-H2, lymphoblastic leukaemia, human rhabdomyosarcoma, human breast carcinoma, human Burkitt's lymphoma, human lung carcinoma, human Ewing's sarcoma, human glioma and human osteosarcoma.