The 41-year-old German is manager Arsene Wenger's solution to his goalkeeping crisis after injuries to Wojciech Szczesny, Lukasz Fabianski and Vito Mannone left the Premier League club with only one fit experienced keeper in Manuel Almunia.
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"Arsenal have a goalkeeping emergency at the moment and I am more than happy to jump in," Lehmann told German paper Bild.
Lehmann left Arsenal in 2008 after five years at the club to join VfB Stuttgart and called time on his 22-year career last May.
Lehmann, who began his career at Schalke 04 before stints at AC Milan and Borussia Dortmund, made almost 200 apearances for Arsenal and was an ever-present in the "Invincibles" team that won the Premier League title without losing a match in 2003-04.
He was a controversial figure known for his explosive temper which led to frequent run-ins with team-mates and referees.
Lehmann helped Arsenal reach the Champions League Final in 2006 but became the first goalkeeper to be shown a red card in the showpiece game when he fouled Samuel Eto'o early in their defeat by Barcelona.
His international career was limited by the presence of Oliver Kahn who restricted Lehmann to just 61 caps.
Arsenal have been knocked out of three competitions in the last two weeks, leaving the Premier League title as their final chance this season to win their first trophy for six years.
They are three points behind leaders Manchester United with a game in hand.
