The profit, achieved effectively by the sale of Robin van Persie to Manchester United, also accompanies an increased figure of £123.3million in cash reserves, up £7million.
The figures are for the half year to the end of November 2012.
Arsenal chairman Peter Hill-Wood said: "Our ability to compete at the top of the game here and in Europe is underpinned by our financial performance which gives the club strength and independence.
"Our desire is to make everyone connected with Arsenal proud of the club. We know that comes through winning trophies but also through the way we do things and that will remain our constant guide."The financial report states the that "profit on sale of player registrations amounted to £42.5million" - down from £63million in 2011 but still a cause of concern to those fans who believe Arsenal have not replaced players such as Van Persie and before him Cesc Fabregas by those of similar quality.
Hill-Wood insisted however that was not the case.
He added in a statement: "Let me be quite clear that our intention is to keep our best players and recruit new talent to make us stronger.
"Although we were disappointed to see Robin van Persie leave the club, we have taken steps to secure our best players going forward and have recently signed Jack Wilshere, Theo Walcott, Kieran Gibbs, Aaron Ramsey, Alex Oxlade-Chamberlain and Carl Jenkinson to new long-term contracts.
"During this financial period we also invested £40.9million in the acquisition of new players, Lukas Podolski, Santi Cazorla and Olivier Giroud, and the extension of other player contracts. More recently we added Nacho Monreal to our ranks from Malaga."
Hill-Wood said that the Premier League club's agreement to bring in financial fair play-style spending controls would help Arsenal.
He said: "These new rules will be good for us, good for the Premier League and good for the game as a whole.
"It is important that we maintain the quality and level of competition if the game is to continue being a compelling spectacle and we believe the introduction of tighter financial regulation will assist all clubs to compete while remaining financially responsible."
Arsenal's football turnover dropped from £113.5million to £106million as a result of four fewer home fixtures compared to the same period last year. The report also confirmed an extended partnership with Emirates which will be worth up to £150million.
Hill-Wood added: "The Emirates partnership is one of the biggest sponsorship deals in the game and is an endorsement of the commercial approach we are taking."