The Bristol-based firm recorded a massive £402,249 rise in its profits, from £162,616 in 2005 to £564,865 at the end of 2006.
According to the practice, the impressive results are an accumulation of successful acquisitions and significant project wins.
Stride Treglown chairman Kevin Steer said: 'It has been a very good year. We have increased our number of staff from 200 to 270, and moreover we have some significant new projects coming into the office.
'We also acquired a small Manchester-based practice called Chapman Robinson, which specialises in urban regeneration, which we think is a very important area at the moment.
'We have seen a variety of our sectors grow, such as retail, commercial, and residential - especially regenerating dockside areas. And we have won major schools projects in West Sussex, Bognor Regis and Wiltshire through the Building Schools for the Future programme,' added Steer.