Chlorophene, a chlorinated phenolic compound and a well‐known emerging pollutant due to its extensive use as an antimicrobial agent, has been identified in a local backwater stream using liquid chromatography quadrupole time of flight MS (LC‐Q‐TOF‐MS). The concentration of chlorophene has been calculated as 6 × 10⁻⁷ mol L⁻¹ (0.132 ppm). In order to develop a suitable treatment protocol, ultrasound mediated oxidative degradation has been carried out. Prior to the investigation of chlorophene in the backwater sample, the degradation in pure water has been investigated at 620 kHz and 40.25 W mL⁻¹. Complete disappearance of chlorophene was observed within 40 min of sonication. The presence of various inorganic ions had no significant influence on the degradation. A complete chemical oxygen demand removal in the local backwater samples was achieved within 3 h of sonication. Three major intermediate products have been identified by LC‐Q‐TOF‐MS and a plausible mechanism of the degradation is proposed. The same method was applied for the backwater sample containing chlorophene with a concentration of 6 × 10⁻⁷ mol L⁻¹. Complete disappearance of chlorophene and nearly 85.7% COD removal was observed in this system as well.