The Oslo region has seen a substantial increase in the immigrant population during the last five decades. In Oslo, as in many other European cities, the non-Western population is far from evenly distributed throughout the city. The aim of this thesis is to explore developments in neighbourhood concentrations of non-Western immigrants with a specific focus on adult descendants of Turkish, Moroccan, Indian, Pakistani and Vietnamese immigrants. The main inquiry is whether and to what extent non-Western immigrant descendants integrate spatially in adulthood, in terms of settling in neighbourhoods that are characterised by similar levels of non-Western immigrant population, as compared with their ethnic Norwegian peers. Variables measuring social background characteristics, as well as, socioeconomic and cultural resources are explored in order to identify associations between these and the proportion of non-Western immigrant population in the neighbourhoods where the descendants settle as adults. Moreover, associations between proportion of non-Westerners in the descendants’ origin and destination neighbourhood are explored. The analysis follows a modified version of Alba and Logan’s (1993) locational attainment model, which is based on OLS regressions, and employs register data on Western and non-Western immigrant descendants and their ethnic Norwegian peers in the birth cohorts of 1974-1980 who resided in the Oslo region at age 16 (1990-1996). The theoretical framework supporting the analysis is composed of three prevailing theoretical models in the international research literature on ethnic residential segregation: 1) The Spatial Assimilation Model, 2) The Place Stratification Model, and 3) The Ethnic Enclave Model. The analysis finds that non-Western descendants settle in neighbourhoods with, on average, higher non-Western population proportions, as compared with ethnic Norwegian peers on equality of characteristics. The largest differences apply to Pakistani and Turkish descendants as well as for female Moroccan descendants, while the average differences are moderate among Indian and Vietnamese descendants. In fact, female Indian and Vietnamese descendants are not predicted to settle in neighbourhoods with, on average, higher non-Western population proportions than equivalent female ethnic Norwegian peers. The same applies to Western immigrant descendants. However, mechanisms of spatial assimilation are found among other non-Western immigrant descendants as well. When comparing individuals with specific levels of socio-economic resources (measured as education and income levels) and cultural resources (measured as partner’s country-of-origin) the average differences in the proportions of non-Western immigrant population between the neighbourhoods of non-Western descendants and equivalent ethnic Norwegian peers are predicted to be lower among individuals with higher education, incomes and/or who cohabit with partners of ethnic Norwegian descent. Nevertheless, these mechanisms are not equally strong for descendants in all non-Western groups. They seem to be especially weak among male Pakistani descendants. Stronger mechanisms of spatial assimilation were found among female Indian and Vietnamese descendants, as they are not predicted to settle in neighbourhoods with, on average, higher non-Western population proportions compared with equivalent female ethnic Norwegian peers with similar incomes and partner status. Spatial assimilation set aside, non-Western descendants are largely found to reproduce their parents’ neighbourhood patterns, even in cases of equality with majority peers. Those who were raised in neighbourhoods with the highest non-Western population proportions are also predicted to settle in neighbourhoods with the highest proportions, as compared with equivalent ethnic majority peers raised in similar neighbourhoods. Their ethnic Norwegian peers are, on the other hand, found to settle in neighbourhoods with, on average, moderate proportions of non-Westerners even when raised in neighbourhoods with proportions. The largest differences were found for Turkish and Pakistani descendants raised in neighbourhoods with the highest non-Western population proportions. These findings indicate that preferences for ethnic neigh-bourhoods might be prevalent among non-Western immigrant descendants, at least among Turkish and Pakistani descendants. However, it is also conceivable that structural hindrances, such as ethnic housing discrimination, impair non-Western descendants from relocating to the neighbourhoods they wish to settle in. In total, female Indian and Vietnamese descendants are found to be the most spatially integrated non-Western descendants examined in this study. Compared with equivalent female ethnic Norwegian peers, they are predicted to settle in neighbourhoods with, on average, similar non-Western population proportions regardless of the proportions in their origin neighbourhoods.