Acculturation has been characterized as an important variable in the mental health of ethnic migrant groups. This dissertation developed and assessed multidimensional measures of acculturation and ethnic attachment for Korean Americans based on a random sample of first-generation immigrants from Chicago (N = 622) and a sample of students from the University of Michigan (UMI) (N = 206). Factor analysis revealed four interpretable acculturation factors and six ethnic attachment factors among the Chicago sample. Five distinct acculturation factors and three ethnic attachment factors emerged among the UMI sample with Cronbach alpha estimates for each of the factors ranging from very high to moderate. In both samples, the results supported a multidimensional conceptualization of acculturation. Also, the results obtained provided evidence supporting the validity of the scale, which is promising for measuring level of acculturation among Korean American populations.