The effects of freeze-thaw processes on a natural silt soil stabilized with Class C fly ash and cement are investigated in this study. The silt was obtained from Soma near the city of Izmir, Turkey. The experimental study consisted of stabilizing the cylindrical soil specimens with fly ash and cement at various rates by compacting and then curing these specimens up to 28 days in a moist room at a constant temperature and controlled humidity. Specimens were separated into two groups: half of them were protected by a stretch film to prevent desiccation; the remaining were unprotected. After curing, specimens were subjected to a maximum of seven cycles of closed-system freezing and thawing. Then, unconfined compressive strength (UCS) tests were conducted on all specimens and the results were evaluated in terms of the amount of cementitious material included, curing conditions and the number of cycles. As a consequence, it was noted that specimens of high fly ash and cement content had greater strength values. (C) 2008 Elsevier B.V. All rights reserved.