BACKGROUND: A lesion on an occlusal tooth surface with no cavitation and no radiographic radiolucency but in which caries is suspected owing to surface roughness, opacities, or staining can be defined as a suspicious occlusal carious lesion (SOCL). The authors' objective was to quantify the characteristics of SOCLs and their relationship to lesion depth and activity after these lesions were opened surgically. METHODS: Ninety-three dentists participated in the study. When a consenting patient had an SOCL, information was recorded about the tooth, lesion, treatment provided, and, if the SOCL was opened surgically, its lesion depth. The Rao-Scott cluster-adjusted chi(2) test was used to evaluate associations between lesion depth and color, roughness, patient risk, and luster. RESULTS: The authors analyzed 1,593 SOCLs. Lesion color varied from yellow/light brown (40%) to dark brown/black (47%), with 13% other colors. Most (69%) of SOCLs had a rough surface when examined with an explorer. Over one-third of the SOCLs (39%) were treated surgically. Of the 585 surgically treated SOCLs, 61% had dentinal caries. There were statistically significant associations between lesion depth and color (P = .03), luster (P = .04), and roughness (P = .01). The authors classified 52% of the patients as being at elevated caries risk. The authors found no significant associations between lesion depth and patient risk (P = .07). CONCLUSIONS: Although statistically significant, the clinical characteristics studied do not provide accurate guidance for making definitive treatment decisions and result in high rates of false positives. PRACTICAL IMPLICATIONS: Given that 39% of the opened lesions did not have dentinal caries or were inactive, evidence-based preventive management is an appropriate alternative to surgical intervention.