Purpose: To determine the sorption and solubility properties of soft liners in relation to the aging process. Materials and methods: Five soft liners (Flexor, Molloplast B, Ufigel L, heat-cured; Simpa, Ufigel P, cold-cured) were used. The sorption and solubility tests were performed as outlined in the American Dental Association (ADA) specification 12 for denture base polymers. Ten specimens of each material were fabricated. One set of five specimens was subjected to accelerated aging process in the Weather-Ometer instrument. The test materials were dried in a desiccator and then immersed in distilled water at 37 +/- 1 degrees C for 15, and 30 days. The sorption behavior of the test specimens was calculated. The solubility behavior of the test materials was determined only after 30 days. Results: Aged materials immersed in water for 15 days showed different sorption properties related to the material. After water immersion for 30 days, the materials showed increased sorption properties. Negative increase in solubility was determined after aging for all liners except Flexor.