The purpose of the study was to develop a multifactorial model for the prediction of 11-month caries increment in adolescents. The mean age of the subjects (n= 181) at the base-line examination was 13 years and 3 months. The risk indicators consisted of past caries experience, white spot lesions, visible plaque, gingivitis, salivary secretion rate, buffer effect, sucrase, mutans streptococci, lactobacilli, andCandida. The multifactorial modeling included all the above risk indicators, age, and gender and resulted in different models in boys and girls, indicating the difficulty of caries prediction in adolescents. When boys and girls were combined, the final model included past caries experience,Candida, and salivary sucrase. Although the accuracy of the model was slighdy below die 80% level recommended for screening purposes, the results provide clinically valuable information. The risk of caries increases with an increasing number of positive tests within the model