Traditional Chinese medicine (TCM) syndrome, also known as TCM ZHENG or TCM pattern, is an integral and essential part of TCM theory that helps to guide the design of individualized treatments. A TCM syndrome, in essence, is a characteristic profile of all clinical manifestations in one patient that can be readily identified by a TCM practitioner. In this article, the authors reviewed the presentations of TCM syndromes in seven common malignancies (liver, lung, gastric, breast, colorectal, pancreatic and esophageal cancers), the objectivity and the standardization of TCM syndrome differentiation, the evaluation of TCM syndrome modeling in cancer research, and syndrome differentiation-guided TCM treatment of cancers. A better understanding of TCM syndrome theory, as well as its potential biological basis, may contribute greatly to the clinical TCM diagnosis and the treatment of cancer.