In the present article it is described the validation of a simple, precise, accurate, rapid and low-cost UV spectrophotometric method for the quantification of acetylsalicylic acid in pharmaceutical formulations. The method was validated by linearity, specificity, range, accuracy, precision, robustness, and limits of detection and quantification. The method was linear in the range between 24-36 μg mL-1 , presenting a good correlation coefficient (r = 0.9994) and adequate limits of quantification (6.57 μg mL-1) and detection (1.99 μg mL-1). Precision analysis showed low coefficient of variation (< 2.0%) and a good average recovery percentual (99.42%reference and 95.94%-generic). The results and the statistical treated proved that the method may be considered a precise, accurate and low cost analytical alternative for laboratory routine and experimental activity. The method was applied for acetylsalicylic acid determination in two different pharmaceuticals formulations. The results of these analyzes are in accordance with the values declared by the manufacturer, at a 95% confidence level. This experimental activity is a simple and might be used as an practice activities on teaching laboratories improve the student learning.