Amnesty International in Poland estimated that local activists wrote that many appeals for Adnan Hajizada and Emin Milli during a letter-writing marathon marking human rights day on December 10.
Milli and Hajizada, who had written critically about Azerbaijan's government, were jailed for 2 1/2 and two years last month on hooliganism charges in a case international rights groups say is politically motivated.
Their case was among 15 from around the world highlighted at the Polish letter-writing event.
The letters call on Azerbaijan's president, justice minister, and ombudsman to take all the necessary steps to release the bloggers unconditionally and immediately as Amnesty considers the young activists prisoners of conscience.
"The bloggers' case is one of those which are especially urgent now," Wojciech Makowski, the Amnesty Marathon Coordinator in Poland, told RFE/RL, explaining why the case was highlighted.
"It was recommended by Amnesty International Secretariat to include it in this year's marathon. Besides, the bloggers visited Poland and they have many friends here."
This year's Amnesty International Letter-Writing Marathon beat a record in Poland, with activists penning more than 100,000 letters for prisoners of conscience and human rights defenders who remain under threat all over the world.
The 24-hour action was held in more than 100 Polish towns. This year, Warsaw beat its own record established last year at 78,000 letters.
"It is a very good result, though obviously it is not numbers that are important but how effective and successful our letter-writing could be and what will eventually happen to all these individuals we are writing for," Makowski said. "Among the last year's cases, seven ended in a positive way for the addressees."
The Global Letter-Writing Marathon originated in Poland. It was held for the first time in 2001.
This year, 38 countries all over the globe joined the event to mark the anniversary of the Universal Declaration of Human Rights, adopted on December 10, 1948.