The amnesty was proposed by Ulrich Goll, the justice minister of Baden-Württemberg, the state where 17-year-old gunman Tim Kretschner murdered 15 people in a shooting spree in the town of Winnenden before being killed by police on March 11.
Goll came up with the idea of an amnesty after locals in the county where Winnenden is located turned in over 370 unregistered weapons to the police after the attacks. Many of the weapons were either inherited or had long been unused.
Representatives from the states will draw up plans for a weapons amnesty by mid-May. Anyone owning an unregistered weapon would have to turn it in within an as-yet undetermined amount of time to avoid prosecution.
Since the attack, gun control has become a hot political issue in Germany. A recent poll by Emind showed 72 percent of those surveyed Emind thought gun control laws should be tightened. Another poll by Stern magazine showed 59 percent of Germans supported banning storage of firearms and ammunition in private households.
Germany has been shocked by a number of fatal school shootings in recent years.
In February 2002, a 22-year-old gunman killed the headmaster and seriously injured another person in a vocational training centre he attended at Freising, near Munich.
Two months later, 16 people were killed at a high-school in Erfurt in eastern Germany, by a 19-year-old former student, who then killed himself.
In November 2006, a former student at a vocational school in Lower Saxony in northwestern Germany went a shooting spree in the establishment, injuring 37 people before turning his gun on himself.