The purpose of this study was to investigate radiographic predictors of impacted maxillary canine related to the duration of treatment time. A total of twenty-four maxillary impacted canines with surgical exposure and orthodontic treatment were collected. The average age of the patients was 13.7 years at the beginning of treatment and the study included 9 males and 14 females. There were sixteen impacted teeth on the buccal side and eight on the palatal side. Four panoramic radiographic predictors including canine angulation, mesiodistal position, vertical position and root formation related to the duration of orthodontic treatment were assessed. The duration of treatment was defined from beginning of orthodontic traction to alignment and leveling with .016＂ x .016＂ stainless steel archwires. In terms of statistics, a multiple regression analysis was used. The results showed that the mesiodistal position of the impacted canine was statistically significantly related to the duration of orthodontic treatment (p=0.000). However, there was no significant correlation between canine angulation, vertical position, or the root formation of the impacted canine and the duration of orthodontic treatment. It was concluded that the mesiodistal position of the impacted canine was a predominant predictor of the duration of orthodontic treatment.