Around a dozen same-sex couples are expected to marry in Berlin on Sunday, with a similar number due in Hamburg, gay rights organizations said, taking advantage of the decision of some registries to open on a day when they are normally closed.
Among them are Karl Kreile, 59, and Bodo Mende, 60, who will at 9.30 local time (0730 GMT) become Germany's first married gay couple when they say "yes" in the town hall of the Berlin borough of Schoeneberg after 38 years together.
"We have finally achieved legal equality," Mende told a news conference on Friday. "It's been 25 years' of hard struggle to secure this."
Germany's parliament approved marriage equality in June after Chancellor Angela Merkel chose to make the vote a matter of conscience, freeing many of her Social Democrat coalition partners and many of her conservative lawmakers to vote for it.
Rights organizations say more needs to be done to achieve full equality. It is still impossible for children born into a lesbian couple to have both parents as a legal mother.
Kreile and Mende, who registered their civil partnership 15 years ago, shortly after it became legal to do so in Germany, first tried to marry a quarter of a century ago.
"I remember how it felt when we went to the registry office in Berlin Charlottenburg to request marriage," said Kreile, describing a publicity-raising campaign he and his partner had participated in.
"The official was nice, and so were the couples before and after us in the line, telling us: 'We understand what you want.' But afterwards I still had to feel a sense of shame. I felt discriminated against, being sent out again," he added.Some technical problems remain. The government's registry software recognizes only opposite-sex marriages and will only be updated next year. Until then, even same-sex couples will be recorded as "husband" and "wife."