Background: Binders are the prominent inactive ingredient in development of solid dosage form. Varieties of natural and synthetic binders are available and many are in use by pharmaceutical industry. The scope of identifying the need of binder with different property and varying viscosity still exists. Sargassum wightii is brown seaweed belongs to the class Phaeophyceae, is widely distributed in tropical and temperate oceans. It belongs to the family Sargassaceae and order Fucales. Method: Aqueous soxhlet extraction method was used for the extraction of gum. The extracted gum was incorporated as binder in the formulation of tablets using Acyclovir as the model drug by wet granulation method. The prepared acyclovir tablets were compared with tablets prepared using standard binders such as Acacia and Methyl cellulose. Results: The result shows that the granules prepared with Sargassum wightii binder shows good flow properties as that of Acacia and Methylcellulose and can be compressed into tablets. The prepared Acyclovir tablets with Sargassum wightii shows good result for friability and hardness test from a concentration 12.5 to 25%. The prepared tablets get disintegrate within 3 minutes and shows a complete drug release within 1 hour. Conclusion: Hence on comparing with Acacia and Methyl cellulose Sargassum wightii binder shows good binding property and safely be used as a pharmaceutical binder for the formulation of tablets.