Effects of freezing and thawing on the mechanical behavior of silty soils stabilized with fly ash are investigated in this study. Laboratory based analyses required to obtain efficient fly ash addition rates and compaction procedure are discussed. Examples of laboratory evaluations are presented using silty soils. The soils are natural silts obtained from the vicinity of Izmir City, Turkey. Additionally, the effect of weakly cementation on the mechanical behavior of silt stabilized by fly ash is also studied experimentally. The cementing agents are cement and fly ash slurry, and the samples so formed were somewhat cemented. Sity soils are stabilized by 10% and 30% percents of fly ash, as well as 2% and 8% percents of cement. After the compaction process in proctor densification, uniaxial tests are performed on the silty samples for various freezing and thawing cycles (one, three and seven) under different curing conditions. It is concluded that the influence of freezing and thawing on the mechanical behaviour of silty soils must be considered with the ratio of stabilization materials and curing conditions.