The synthetic dyes from industrial discharges cause water pollution when directly discharged into water bodies due to their bright colour, complex structure, persistence nature and adsorption is found to be a simple and cost effective method for decolourizing synthetic dyes. This research is carried out to investigate the effect of adsorbent size and dose of eco-friendly, cost effective adsorbent from waste Pisumsativum pods on the decolourization efficiency of synthetic dyes (Crystal Violet, Methylene Blue and Malachite Green).For MG dye, Pisumsativum pod adsorbent size of 0.246 mm is good for its removal whereas for CV and MB dyes, the adsorbent size of 0.604 mm is better. Further the adsorbent dose of 0.5 gm is suitable to remove colour of CV dyes and 1 gm is needed to decolourize MG and MB dyes to a good extent. Also this research has revealed that adsorption capacity decreases with increasing adsorbent dose for all the three dyes.