4:2 compressors are basic components in the design of parallel multipliers. Low power consuming 4:2 compressors can result in a significant reduction of power when realizing power-efficient multipliers in any low power oriented systems. In the area of low power integrated circuit design, adiabatic switching technique has received considerable attention in the recent years. Many adiabatic logic architectures have been reported. In this letter, a low power 4:2 compressor circuit based on the adiabatic switching principle is proposed. When simulated using HSPICE, it was shown that the proposed circuit consumed very much less power than the static CMOS version.