Background: Conclusions about differences in union dissolution rates between same-sex couples and different-sex couples vary across studies and countries. Previous research identifies same-sex couples solely using information on the sex of partners.

Objective: To investigate how the measures used to identify same-sex couples affect conclusions regarding differences in dissolution rates between different-sex and same-sex unions in the stigmatized context of Colombia.

Methods: We use rich retrospective data from the Colombian DHS 2015 on the duration of 63,462 unions, including 1,051 same-sex unions. An important feature of this survey is that respondents are also asked about their sexual behavior.

Results: Similar to previous studies on the United States, estimates solely based on the reported sex of partners show that cohabiting same-sex couples are as likely to separate as cohabiting different-sex couples in Colombia. However, excluding same-sex unions of persons who reported never having had sex with someone of the same sex, same-sex unions are considerably more likely to end in separation than different-sex unions.

Conclusions: The same-sex unions of persons who report having had sex with someone of the same sex are more likely to end in separation than different-sex unions in Colombia.

Contribution: We show how substantive conclusions about the relative stability of same-sex unions depend on how same-sex unions are identified. To reduce the influence of possible miscoding on conclusions we recommend combining various measures to identify same-sex unions.