Abstract <p>This study explores the application of proton nuclear magnetic resonance (^<b>1</b><b>H NMR</b>) spectroscopy for the simultaneous determination of acetic acid and ethanol concentrations in commercial vinegar samples, eliminating the need for prior separation procedures. The method demonstrated an average error of 10.53% for acetic acid and between 3.63 and 5.68% for ethanol, depending on the spectral peak analyzed. Inter-day analysis over a week yielded average relative standard deviations of 0.81% for acetic acid and 1.53 to 2.36% for ethanol, indicating high precision. Notably, the results revealed significant adulteration in the vinegar industry, with only 5 out of 12 samples meeting acceptable acetic acid concentrations (5–8%), while nearly half of the samples contained ethanol levels exceeding the maximum allowable concentration. This study underscores the efficacy of ¹H NMR spectroscopy as a reliable technique for quality control in vinegar analysis.</p>