A near real-time, sensitive and reliable method of detecting airborne Bacillus anthracis spores by air sampling (wet mode) and then exposing the collected sample to an antibody-functionalized piezoelectric-excited millimeter-sized cantilever (PEMC) sensor is presented. Using a commercial air sampler, a 10min air sample at 267L/min captured the airborne particulates containing Bacillus anthracis (BA) spores and concentrated them into 5mL of phosphate buffered saline (PBS). This sample was then injected into a flow cell containing an antibody-functionalized PEMC sensor. The resonant frequency of the PEMC sensor at 925.1kHz decreased exponentially as the BA spores attached to the sensor surface producing a positive response well beyond the noise level in 2min and reached a steady state value in 20min. In liquid phase, the sensor response correlated well (R 2 =0.99) with spore concentration and was shown to follow: [Response in Hz]=(0.0637)×(spore concentration in #/mL). Our results show that detection of 38BA spores/L of air is achievable in near real-time with an estimated lower limit of detection of ∼5spores/L of air in the configuration tested.