Same-sex couples are one component of the growing diversity of family and partnership situations in Europe. Data from six countries that took part in the Generations and Gender Survey (Belgium, France, Germany, the Netherlands, Norway, and Sweden) were used to analyse the respondents’ partnership histories and the sex of current and previous cohabiting partners. After correcting for the coding errors inherent in this type of survey, a Cox model was used to compare the separation risks of different-sex and same-sex couples. The results show that the unadjusted separation risk for same-sex couples is 2.4 times higher than that for different-sex couples, but that this risk decreases after the independent and control variables are included in the model. Marriage and the presence of children, less frequent among same-sex couples, are two key factors that increase the stability of different-sex unions.