Four tenants have signed leases totaling 52,326 square feet at the Riverworks complex at 480 Pleasant St. in Watertown.

New England Research Institute, which is relocating in July from 9 Galen St. in Watertown, will occupy 33,658 square feet on three floors. pSivida, which makes drugs that treat eye diseases, is moving from 400 Pleasant St. in Watertown and will occupy 13,650 square feet. Newton-based web design and marketing agency Digital Impulse leased 2,597 square feet, and sports marketing agency TRACS Inc. of Watertown leased 2,422 square feet.

The 200,000-square-foot complex was the headquarters of Boston Scientific in the 1980s. It consists of two connected mill buildings along the Charles River. It recently added a new cafeteria and fitness center, a new main entrance along Pleasant Street, an interior courtyard with outdoor seating and more than 100 new windows. The complex is currently 82 percent leased.

Jones Lang LaSalle represented landlord Farley White Interests of Boston in its negotiations with the tenants and also represented NERI. Cassidy Turley represented pSivida. Cushman & Wakefield represented Digital Impulse and Newmark Grubb Knight Frank represented TRACS.

Editor’s Note: This article has been updated to reflect that Cassidy Turley represented pSivida.