The Glasgow-based practice was handed the award from the Chicago Athenaeum: Museum of Architecture and Design.
Murray and Dunlop's project was put forward for the award by Italian architect Massimiliano Fuksas, and was then judged by a panel of Russian judges.
The workshop project was completed in 2005 and provides single-storey industrial units for small businesses ( click here to see the AJ building study ).
The practice said it was delighted by the news, even though it had been unaware it had been entered.
Alan Dunlop said: 'It came as a complete but delightful surprise. To think that a low-key workshop project could win such a top award from Chicago and be put forward by Fuksas is uplifting and emphasises an approach we've always taken as a practice that there can be architecture in even the most basic of commissions.
'It's funny though that this small project should gain such international attention but great for us and for Clydebank to be mentioned on a world stage.'