The authors report on 4,624 noncancer women classified by telethermography (TH1-2 vs TH3) and followed for an average of 6.6 years (range, 2-12). Breast cancer occurring beyond the sixth month from TH were recorded according to a Cancer Registry, and the association between breast cancer incidence and thermographic class or patient age was evaluated. Univariate analysis showed a significant association of age and thermography with further cancer incidence, but multivariate analysis (Cox's model) confirmed a significant association only for age. Thermography (TH3) showed a nonsignificant odds ratio of 1.6 with respect to TH1-2 cases. Thus thermography did not show any practical role as a breast cancer risk indicator. Possible biases affecting previous reports suggesting the use of thermography as a breast cancer risk indicator are discussed.