Fava bean peels, Vicia faba (FBP) are investigated as biosorbents for the removal of Methylene Blue (MB) dye from aqueous solutions through a novel and efficient sorption process utilizing ultrasonicassisted (US) shaking. Ultrasonication remarkably enhanced sorption rate relative to conventional (CV) shaking, while maintaining the same sorption capacity. Ultrasonic sorption rate amounted to four times higher than its conventional counterpart at 3.6 mg/L initial dye concentration, 5 g/L adsorbent dose, and pH 5.8. Under the same adsorbent dose and pH conditions, percent removal ranged between 70-80% at the low dye concentration range (3.6-25 mg/L) and reached about 90% at 50 mg/L of the initial dye concentration. According to the Langmuir model, maximum sorption capacity was estimated to be 140 mg/g. A multiple linear regression statistical model revealed that adsorption was significantly affected by initial concentration, adsorbent dose and time. FBP could be successfully utilized as a low-cost biosorbent for the removal of MB from wastewater via US biosorption as an alternative to CV sorption. US biosorption yields the same sorption capacities as CV biosorption, but with significant reduction in operational times. Considerable amounts of synthetic dyes are used in many process industries. Textile, pharmaceutical, leather, food processing, cosmetics, and paint industries discharge into the environment about 10-15% of over 0.8 million ton of several types of dyes produced annually worldwide. It is projected that the dye business will grow annually by about 2-3% due to the increased global production and consumption of dyes. In developing countries like India and China, the production rate of dyes is increasing steadily every year. Without proper treatment, these dyes harm the environment, marine life and pose serious health threats to humans particularly upon degradation as they become toxic, recalcitrant, mutagenic, and carcinogenic 1-3. Methylene blue (MB) (3,7-bis(Dimethylamino)-phenothiazin-5-iumchloride) is a thiazine cationic dye commonly used for biological staining as well as coloring paper, hair, cottons and wools 4. In addition, MB injection is used in the treatment of methemoglobinemia and urinary tract infections. However, accumulation of MB in wastewater has adverse health effects such as difficulties in breathing, vomiting, eye burns, diarrhea and nausea 5. Several physicochemical and biological processes have been successfully carried out in order to treat dye effluents 6 , examples of which are membrane filtration 7 , photocatalytic degradation 8 , irradiation 9 , biological treatment 10 , conventional adsorption 11 and ultrasonic-assisted adsorption 12. Adsorption is a commonly employed strategy due to its relative facile operation, availability of its adsorbents, selectivity and potential for scale-up. Among employed adsorbents, activated carbon is commonly used due to its efficiency and high surface area 13. However, it has substantial limitations due to its high cost of regeneration and its imp...