A thermoacoustic refrigerator (TAR) of miniature scale, aimed for low-capacity cooling, was numerically and experimentally investigated. DeltaE (Ward and Swift, 1994) was used to model and optimize the TAR design. MEMS stacks, along with several other materials, were used to produce cooling. The precise control over dimensions and geometry that MEMS technology provides can be critical to cooler performance. A commercial PZT driver was used in this study to deliver acoustic power for heat pumping. The cooler is 1/4λ long in standing-wave configuration and operated at 4 kHz, where the acoustic resonance resides. TAR in other geometry and using in-house drivers were also developed but are not included in this paper (Chen et al., 2002). A pressurized version, aimed for higher power density and efficiency using inert gas mixtures, is under development. The performance, challenges, and a system test bed using Lab VIEW are reported.