This paper analyzes the determinants of assortative mating by ethnicity and education for individuals with an immigrant background in Sweden, focusing on the role of individual, marriage market and parental characteristics. Results indicate that higher levels of host country specific human capital decrease the likelihood of ethnic endogamy and increase the likelihood of educational homogamy. Opportunity as measured by sex ratios and relative group size is found to be positively correlated to both types of assortative mating. Parental assortative mating (ethnic/educational), as a measure of group identity, is found to increase the likelihood of assortative mating. A comparison of marginal effects, by gender, suggests that the social boundaries defined by ethnicity and education in the marriage market are relatively more easily crossed by men with the accumulation of local and general human capital. Likewise, the influence of group identity appears to matter more for women when marriages are based on ethnicity but matter more for men when marriages are based on education. Key words: assortative mating, immigrant background, ethnicity, educational level, marriage market, parental characteristics, sex ratio, group size, gender