The study compared the visual properties of the tongue according to traditional Chinese medicine in 60 patients with current cancer and 60 healthy subjects without a history of cancer. Three independent TCM experts evaluated 20 predefined characters based on three standardized photographs of the tongue. Six features were significantly associated with the presence of cancer (FDR q < 0.05): desquamated coating (OR = 3.66, 95% CI 1.40–9.60), spidery sublingual veins (OR = 2.62, 95% CI 1.53–4.92), thick coating (OR = 2.56, 95% CI 1.50–4.36), purple tongue body (OR = 2.29, 95% CI 1.44–3.63), tooth marks (OR = 1.87, 95% CI 1.19–2.95) and thin coating (OR = 0.38, 95% CI 0.22–0.65). Inter-rater reliability of ratings was mild to moderate (Fleiss κ ≈ 0.01–0.48). Discriminative power of the models was moderate (AUC 0.676–0.736). The authors emphasize that the findings are exploratory, with variable reliability, and should not be used for diagnosis without further validation in larger studies.