A protocol created for acephate detection on particulates and vapors surrounding farmworkers as well as in urine samples is reported. Acephate is detected to the low parts-per-billion (ppb) range using surface-enhanced Raman spectroscopy (SERS). Optimal SERS sensor metal choice and post-production treatments to improve sensor stability in aqueous solutions containing acephate are presented. Acephate is detected in the vapor phase and can be differentiated from urine components and structurally similar pesticides, including the acephate metabolite-degradation product methamidophos. Protocol evaluation and preliminary field tests from North Carolina farms are discussed.