Purpose: We analyzed to find out prognostic factors in the conservative treatment for the plantar fasciitis. Materials and Methods: The data were collected from 145 patients, 159 feet (M:F = 51:108) with conservative treatment and analyzed for possible prognostic factors : sex, age of onset, the duration of symptom before treatment, pain score before treatment, the duration for symptom remission, medication period, calcaneal pitch angle, and presence of calcaneal spur. Results: The duration of symptom before conservative treatment is affected to the prognosis, and the borderline of the effective period was about 6 months. Conclusion: With the conservative treatment of the plantar fasciitis, we found that (1) the duration of symptom before the conservative treatment was a prognostic factor, and (2) if the period before the conservative treatment was more than 6 months, the other treatment option such as surgery should be considered for this chronic group.