Hawaii has neither legalized same-sex marriage nor civil unions however the state does provide for Reciprocal Beneficiary Relationships which any two people, who are not married, can register for, including same-sex couples.
In 1998, Hawaiians amended their state constitution to prevent the judicial introduction of same-sex marriage, however the constitution is silent on civil unions and does not prevent the legislature from introducing either same-sex marriage or civil unions.
A bill to create civil unions was proposed in 2007, but was allowed to die.