This paper presents free vibration analysis of pavement bases constructed using sustainable material, a controlled low-strength material (CLSM), using finite element (FE) method. The CLSM concrete is introduced as pavement bases for its special features of easy compaction, high workability and relatively low cost. Rut-resistant stone matrix asphalt is placed on top of CLSM as wearing surface layer. The Young's moduli of CLSM are obtained from laboratory tests for two different binder mixtures, marked as CLSM-B80/30% and CLSM-B130/30%. Two-dimensional planar strain assumption is employed in the FE formulation of steady-state elasto-dynamic analysis of four-layered flexible pavements in which four kinds of different base materials are considered: graded crushed stone, CLSM-B80/30%, CLSM-B130/30% and AC. Comparison study on computed natural frequencies and mode shapes of the flexible pavement using different bases materials will be conducted. Results show that CLSM pavement bases depict higher natural frequencies as compared with graded crushed stone bases and can be suitable sustainable materials employed for pavement design and construction in highway engineering.