Olfactory diagnosis is an important part of the “listening and smell diagnosis” in the four diagnostics of traditional Chinese medicine (TCM)—Inspection, listening/smell, inquiring, and palpation. It differentiates diseases and TCM syndromes by identifying smells. Olfactory diagnosis has a long history in the clinical application of TCM. However, the objectification and standardization of olfactory diagnosis are urgently needed. Embracing the tremendous progress in the fields of analytical chemistry, biomedical engineering and artificial intelligence, TCM has stepped into the “smart” era. This has been contributing to the growing interest in olfactory diagnosis as a non-invasive diagnostic method. This paper provides a review of the research progress in olfactory diagnosis of smart TCM. The research subjects, analytical methods, and scientific instruments of olfactory diagnosis of smart TCM were summarized, the relevant medical applications were outlined, and the current challenges were proposed. The great research value of olfactory diagnosis of smart TCM as well as its future development is also envisioned.

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