Tomasz Czabanski, of Polish foundation Pomost (Bridge), said the troops were reburied during a religious ceremony at a German military graveyard in Poznan, western Poland.
The troops died in the region in January and February 1945, as Soviet forces rolled back the occupying Germans, and were uncovered at various sites earlier this year.
Some 14,000 German soldiers already lie in Poznan's Milostowo cemetery. Czabanski said 200 dog-tags had been found in the mass graves, enabling researchers to put names to some remains.
"The others will remain unknown," he said.
Funded by Germany, Pomost seeks out battlefield burials across Poland and exhumes the remains for reburial in military graveyards.
The exhumation programme is governed by an accord signed by Warsaw and Berlin in 1991.
Since then, some 150,000 German soldiers have been reburied. There are 13 German military cemeteries in Poland. A total of 31,000 soldiers lie in the largest, at Siemianowice Slaskie in the south.
War graves are discovered regularly in Poland, often by accident during construction work.
Some 468,000 German soldiers died in what is now Poland during World War II, and 400,000 during World War I, according to Germany's memorial foundation.
Not all of them died fighting on Polish territory -- the country's borders were shifted westwards into Germany by the victorious Allies to offset land lost to the Soviets in the east.
Sixty-six years after the end of the war, over a million German soldiers and civilians from the Eastern Front and former German territory are still unaccounted for.
Efforts to resolve their fate were hampered by post-war tensions between West Germany and the Soviet-led communist bloc, of which Poland was a part.
But the fall of the Iron Curtain in 1989-1991 brought a thaw, opening the way for the restoration of German cemeteries and a renewed drive to locate long-lost battlefield burials.
Pomost and similar organisations have put aside past hatreds.
Poles have never forgotten the brutality of World War II. Nazi Germany and the Soviet Union invaded and carved up Poland in 1939. On the German side of the line, around six million people were killed, half of them Polish Jews who perished in the Holocaust.
In 1941, Germany turned on its erstwhile ally, and fought its way deep into the Soviet Union. But by mid-1944, Soviet forces pushed the Nazis back into Poland driving towards Berlin, whose defenders surrendered in May 1945.