Romantic relationships can promote better mental and physical health, and thus the processes linked to these outcomes are important to examine. The increased prevalence of intercultural romantic relationships—made up of romantic partners who report having different cultural backgrounds (e.g., differences in ethnicity, race, religion)—offers the opportunity to understand a type of romantic relationship that is not well-studied. By advancing the study of intercultural romantic relationships, science can better determine the generalizability of well-studied relationship processes and may uncover relationship processes that are distinct to intercultural romantic relationships. The study of intercultural romantic relationships also has implications for intergroup relations, a topic of enduring societal importance. The goal of this dissertation was to examine intercultural romantic relationship initiation and maintenance, with particular attention to how specific psychological processes compared to intracultural romantic relationships—made up of romantic partners who report sharing the same cultural background. In Study 1, using self-report survey data from one partner, I examined whether attachment insecurity was associated with the likelihood that individuals had initiated an intercultural romantic relationship in the past or would initiate one in the future. I found that attachment avoidance was associated with a lower likelihood that individuals initiated an intercultural romantic relationship in the past but also that current relationship status was important for this association. In Study 2, using self-report survey data from one partner, I examined whether attachment insecurity was associated with two indices of relationship quality (commitment, and satisfaction) and whether these associations varied as a function of intercultural romantic relationship status. I found that higher levels of attachment anxiety were associated with higher relationship commitment but lower relationship satisfaction. I also found that higher levels of attachment avoidance were associated with lower relationship commitment and satisfaction. These effects did not vary as a function of intercultural romantic relationship status. In Study 3, using self-report data from both partners, I examined whether actor and partner attachment insecurity were associated with actor and partner relationship quality (commitment and satisfaction) and whether these associations differed between the overall sample and intercultural and intracultural couple subsamples. I also examined whether actor and partner attachment insecurity were associated with actor and partner conflict management and whether these associations differed between the overall sample and intercultural and intracultural couple subsamples. These analyses did not yield a consistent pattern of effects, but interesting ancillary findings did emerge. Intercultural couples reported higher levels of relationship commitment but did not have mean differences on any other factors. Taken together, these three studies contribute to the literature on intercultural romantic relationships specifically and relationship science generally.