The Frome colour book and commercial printer was recognised for its work in achieving and maintaining ISO 14001 accreditation.
B&T succeeded because it has shown commitment to empowering its staff through involvement in decision making, the judges said.
In addition to the overall award, B&T picked up the Best Overall Sustainable Waste Management Solution and was shortlisted in two further categories.
B&T manufacturing director Greg Bird and commercial manager Steve Opie were presented with the award by radio presenter Gary Richardson at Cardiffs Millennium Stadium.
B&T also completed production of World Cup 2003 the account of Englands World Cup triumph just a few days after the rugby team lifted the Webb Ellis trophy.
The day after Jonny Wilkinson dropped the winning goal (Sunday), the pages were on press and 150,000 copies of the 160pp book were delivered by the following Thursday.
Story by Lauretta Roberts and Tony Brown
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