Shoosmiths has finished top overall of the Legal Week Employee Satisfaction Report 2013.
And it has come first in the national rankings for a third year running.
The national law firm is described as having a 'great ethos - genuine camaraderie and respect among staff'.
Conducted annually, the legal publication's survey this year assessed 50 firms, basing its findings on around 4,000 completed questionnaires.
Replying to the question 'What is the best thing about your firm?' Shoosmiths respondents this year answered:
. active support for promotion and development
. the culture - we work hard, but have a life outside the office
. opportunities to progress
The report says: "Not only has Shoosmiths retained its number one national spot, but it has surged from 3rd overall in 2012 to 1st this year. This follows seven years of success in the LWI rankings, where it has consistently placed in the top 10.
"Employees are highly satisfied with the quality of clients (8.8) and their interactions with them (8.7), and 18% more likely to recommend their firm to a friend than the average. The firm scores above average on responsibility, health insurance benefits and work/life balance."
Shoosmiths also topped the report's national table in 2011 and 2012.
HR director Louise Hadland told Legal Week: "We have a set of values which guide our every decision, and because of these values, our staff know where they stand.
"We work hard at educating staff about our values - everybody here receives a three-hour session on our values as part of their induction, while each senior appointment is first interviewed by our CEO or chairman to ensure they have the right cultural fit."