The company says it will pay $475 million in cash for PreCision Dermatology of Cumberland, Rhode Island, plus an additional $25 million when a sales-based milestone is passed.
PreCision has about 175 employees and expects to have about $130 million in revenue this year.
Valeant says the deal is expected to close by the end of June and will immediately bolster its profits.
It's the latest acquisition for Valeant.
The company's chief executive has said he wants the company to become one of the top five drug companies in the world by the end of 2016.
"PreCision Dermatology has a wide range of medical dermatology products, treating a number of topical disease states such as acne and atopic dermatitis, and should bring tremendous value to Valeant's medical dermatology portfolio," Valeant chairman and chief executive Michael Pearson said in a statement Monday.
PreCision Dermatology chief executive Bob Moccia said "the combined resources of both companies will create a strengthened competitor, poised to contend with the leading companies in the dermatology market."