In this paper we discuss the design and application of MEMS-based microphones in photoacoustic (PAS) instrumentation, and it is demonstrated that by tailoring the properties of the microphone, tremendous improvements can be achieved in performance of particular importance to photoacoustic detection, such as sensitivity and noise level. Microphones typically used for PAS applications have bandwidths that exceed the requirements by an order of magnitude or more. New microphone designs, with bandwidths specifically targeted towards PAS applications, are shown to have open-circuit sensitivities in excess of 400 mV/Pa and noise levels around 0 dB SPL for a microphone diaphragm as small as 1×1 mm. This gain in performance may lead to a 10×–100× reduction of the detection limit in a state-of-the-art photoacoustic cell. Since the diaphragm in the MEMS microphone is very small, the mass of inertia is also greatly reduced, which leads to a reduction in vibration sensitivity of >10 dB over miniature hearing aid microphones and >20–30 dB over measurement microphones. The reduced vibration sensitivity is critical to push photoacoustic instruments from the laboratory into the field, where high performance rugged instruments are needed for bio-chemical detection.