The work investigates the application of ultrasound for improved extraction of bioactive compounds namely total phenolics, fucose, and uronic acid from brown seaweed (Ascophyllum nodosum). Key process parameters of ultrasonic intensity (UI), extraction time, and solvent type were investigated to optimize extraction yields. The maximum yields on dry basis (db) of total phenolics, fucose, and uronic acid were 82.70 mg GAE/g(db,) 135.76 mg/g(db), and 197.19 mg/g(db), respectively. Maximum bioactive yields were obtained using 0.03 M HCl as solvent at an UI of 75.78 W cm(-2). Extraction kinetics over a 22 hour period were successfully modelled using Peleg's model. This extraction kinetic study demonstrates that ultrasound pretreatment can significantly enhance extraction of bioactives from brown seaweed.