More than 140 firms that participated in a recent survey reported more than €1.1 billion ($1.25 billion) in losses since the sanctions took effect five years ago, the group said.
"The total figure amounts to several billion euros when these numbers are projected onto the entire German economy and the more than 4,500 companies operating in Russia," AHK CEO Matthias Schepp added.
The United States and the European Union imposed sanctions after Russia annexed the Crimean peninsula from Ukraine in early 2014. EU sanctions have had, by contrast, a relatively limited impact on German companies active in Russia, Schepp said.
AHK President Rainer Seele accused the United States of using the measures to pursue its own economic interests at the expense of Germany's "Mittelstand," a collective term for the country's famed small- and medium-sized firms.
"These sanctions are counterproductive, fail to serve their political purpose, drive a wedge between America and Europe and harm everyone in the long term," he said. The EU should, he added, get started with ending its own sanctions against Russia.
The bloc voted to continue the measures at a summit last week. Germany is one of the EU regime's staunchest supporters.
The AHK said 87% of its members wanted German Chancellor Angela Merkel to pursue better relations with Russia by attending more economic events in the country.