This paper presents a novel approach for monitoring fuel adulteration using ultrasonic helical waveguide sensor. The longitudinal L(0,1), torsional T(0,1), and flexural F(1,1) modes were transmitted and received simultaneously through stainless steel helical waveguide. Here, we used shear transducer with 45o orientation of the waveguide axis, following the pulse-echo (PE) concept. We conducted experiments by preparing various fluid samples and altering the blend percentage mixture from 5% to 50%. The combinations included (a) a blend of kero-sene and diesel, (b) a blend of kerosene and petrol, (c) a blend of ethanol and diesel, and (d) a blend of ethanol and petrol. Finding fuel quality at distribution point is critical to prevent fuel adulterations effectively. Monitoring fuel adulteration involves measuring attenuations in the helical waveguide sensor’s reflected signal and velocity of waves. This sensor technique can also detect the ≤ 4% adulterations of fuel by re-configuring the helical sensor. Also, the mea-surement error from the different test samples was discussed based on experimental results. The implementation of this simple technique has potential to detect fuel adulterations at fuel stations and manufacturing plants. That helps to reduce air pollution levels effectively, significantly enhance the performance of automobile engines or fuel-based vehicles.