Gay couples took the historic step of registering as married, the culmination of a three-decade fight for equality.
Shane Lin and Marc Yuan, a couple who fell in love at college, were the first to arrive at a government office in downtown Taipei.
Dressed in matching suits, they embraced and kissed in front of a huge media scrum before signing their marriage certificates.
They were followed by playwright LiYing Chien and her girlfriend, a cartoonist who goes by the pen name Cynical Chick.
Taiwan made history last week when it became the first place in Asia to legalise gay marriage, sparking jubilation among huge crowds of gay rights supporters on the streets of Taipei.
But the issue has also caused deep divisions on an island that remains staunchly conservative, especially outside of the cities and among older generations.
Some 300 same-sex couples are expected to register on Friday, according to local authorities, around 150 in the capital Taipei which boasts a thriving and vocal gay community.
The city hall will co-host an outdoor wedding party near the famous Taipei 101 skyscraper, with local and foreign dignitaries expected to attend.
'Nervous'
Among those planning to tie the knot on Friday was social worker Huang Mei-yu, marrying her partner You Ya-ting.
"I am feeling nervous even though we already had a ceremony in 2012," she told AFP, referring to a religious blessing conducted by a progressive Buddhist master.
"But I am also very happy as it's faster than I had expected. I had thought I would have to wait 10 more years," she added.
Legal recognition of their love, Huang said, was a crucial step and might help others accept the relationship.
"Now that same-sex marriage is legally recognised, I think my parents might finally feel that it's real and stop trying to talk me into getting married (to a man)," she said.
For veteran gay rights activist Chi Chia-wei, Friday's weddings are the culmination of a three-decade long fight trying to persuade successive governments to change the law.
It was Chi who eventually petitioned Taiwan's Constitutional Court leading to a 2017 judgement that denying same-sex couples the right to marry was unconstitutional.
Facing an imminent court deadline, parliament finally passed a bill last Friday allowing same-sex couples to form "exclusive permanent unions" and another clause that would let them apply for a "marriage registration" with government agencies.
"I feel very happy that same-sex couples can finally register and be listed as each other's spouse. I am honoured to witness Friday's marriage registrations," he told AFP.
Conservative pushback
In the last decade Taiwan has placed itself at the vanguard of gay rights in Asia but the issue has polarised society.
Conservative and religious groups mobilised after the court ruling and comfortably won a series of referendums last November in which voters comprehensively rejected defining marriage as anything other than a union between a man and a woman.
Conservative lawmakers put forward rival bills that offered something closer to limited same-sex unions but those measures failed as parliament comfortably passed the gay marriage law.
However, the new law still has restrictions not faced by heterosexual couples.
Same-sex couples can currently only adopt their partners' biological children and can only wed foreigners from countries where gay marriage is also recognised.
Gay rights groups say they are willing to accept partial equality for now in the hopes of winning later legal battles over issues such as adoption, surrogacy and marrying foreigners.
Opponents have vowed to punish President Tsai Ing-wen and the lawmakers who supported the gay marriage law at January's elections when Taiwanese will elect both a new president and a new parliament.