Investigations into the intimate relationships of sexual minorities are proliferating, but often adopt a deficit-oriented and US-centered perspective. In this tri-nation online study with sexual minority participants from Austria, Germany, and Switzerland (N = 571), we (i) assessed the construct validity of the German version of a well-known measure for positive minority identity aspects (the Lesbian, Gay, Bisexual Positive Identity Measure; LGB-PIM), and (ii) explored associations between these aspects (self-awareness, authenticity, community, capacity for intimacy, and social justice) and self-reported relationship quality. Model fit of the German version of the LGB-PIM was deemed acceptable. Higher levels of positive minority identity aspects showed small to moderate associations with higher levels of relationship quality in bivariate analyses, but only capacity for intimacy was linked to relationship quality in higher-order models (controlling for country, age, sexual orientation, gender identity, relationship length, and psychological distress). Results remained robust in several sensitivity analyses. Our results highlight the differential role of positive identity aspects for relationship functioning, with capacity for intimacy as a fruitful leverage point for therapeutic work.